Biosynthesis of mogrosides

Information

  • Patent Grant
  • 12234464
  • Patent Number
    12,234,464
  • Date Filed
    Saturday, November 9, 2019
    5 years ago
  • Date Issued
    Tuesday, February 25, 2025
    2 months ago
Abstract
Provided herein are enzymes (e.g., cucurbitadienol synthases (CDS), UDP-glycosyltransferases (UGT), C11 hydroxylases, epoxide hydrolases (EPH), squalene epoxidases, and/or cytochrome P450 reductases), host cells expressing the enzymes, and methods of producing mogrol precursors, mogrol, and/or mogrosides using such host cells.
Description
REFERENCE TO A SEQUENCE LISTING SUBMITTED AS A TEXT FILE VIA EFS-WEB

The instant application contains a Sequence Listing which has been submitted in ASCII format via EFS-Web and is hereby incorporated by reference in its entirety. Said ASCII copy, created on May 7, 2021, is named G091970023US02-SEQ-FL.TXT and is 949,299 bytes in size.


FIELD OF THE INVENTION

The present disclosure relates to the production of mogrol precursors, mogrol and mogrosides in recombinant cells.


BACKGROUND

Mogrosides are glycosides of cucurbitane derivatives. Highly sought after as sweeteners and sugar alternatives, mogrosides are naturally synthesized in the fruits of plants, including Siraitia grosvenorii (S. grosvenorii). Although anti-cancer, anti-oxidative, and anti-inflammatory properties have been ascribed to mogrosides, characterization of the exact enzymes involved in mogroside biosynthesis is limited. Furthermore, mogroside extraction from fruit is labor-intensive and the structural complexity of mogrosides often hinders de novo chemical synthesis.


SUMMARY

Aspects of the invention relate to a host cell that comprises a heterologous polynucleotide encoding a UDP-glycosyltransferase (UGT), wherein the UGT comprises a region that: corresponds to residues 83 to 92 of wild-type UGT94-289-1 (SEQ ID NO: 109), wherein the region comprises an amino acid substitution relative to residues 83 to 92 of wild-type UGT94-289-1 (SEQ ID NO: 109); and/or corresponds to residues 179 to 198 of wild-type UGT94-289-1 (SEQ ID NO: 109), wherein the region comprises an amino acid substitution relative to residues 179 to 198 of wild-type UGT94-289-1 (SEQ ID NO: 109); wherein the host cell produces in the presence of at least one mogroside precursor at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% more of one or more mogrosides relative to a control host cell that comprises a heterologous polynucleotide encoding wild-type UGT94-289-1 (SEQ ID NO: 109).


In some embodiments, the UGT exhibits at least a 1.3-fold increase in activity (e.g., specific activity) relative to wildtype UGT94-289-1 (SEQ ID NO: 109). In some embodiments, the UGT comprises an amino acid substitution at an amino acid residue located in a structural motif corresponding to a structural motif in wild-type UGT94-289-1 (SEQ ID NO: 109) selected from: loop 6, alpha helix 3, loop 11, alpha helix 6, loop 12, and alpha helix 7. In some embodiments, the UGT is capable of catalyzing conversion of: Mogrol to MIA1; Mogrol to MIE1; MIA1 to MIIA1; MIE1 to MIIE; MIIA1 to MIIIA1; MIA1 to MIIE; MIIA1 to MIII; MIIIA1 to siamenoside I; MIIE to MIII; MIII to siamenoside I; MIIE to MIIIE; and/or MIIIE to siamenoside I. In some embodiments, the UGT is capable of: glycosylation of mogrol at C24; glycosylation of mogroside at C3; branching glycosylation of mogroside at C3; or branching glycosylation of mogroside C24. In some embodiments, the UGT comprises an amino acid substitution at an amino acid residue corresponding to the amino acid residue in wild-type UGT94-289-1 (SEQ ID NO: 109) selected from: H83; T84; T85; N86; P89; L92; Y179; S180; A181; G184; A185; V186; T187; K189; H191; K192; G194; E195; and A198. In some embodiments, the host cell further comprises a heterologous polynucleotide encoding a cucurbitadienol synthase (CDS) enzyme.


Further aspects of the invention relate to a host cell that comprises a heterologous polynucleotide encoding a UGT, wherein the UGT comprises a region that: corresponds to residues 83 to 92 of wild-type UGT94-289-1 (SEQ ID NO: 109), wherein the region comprises an amino acid substitution relative to residues 83 to 92 of wild-type UGT94-289-1 (SEQ ID NO: 109); and/or corresponds to residues 179 to 198 of wild-type UGT94-289-1 (SEQ ID NO: 109) wherein the region comprises an amino acid substitution relative to residues 179 to 198 of wild-type UGT94-289-1 (SEQ ID NO: 109); wherein the UGT comprises less than 90% identity to SEQ ID NO: 109.


In some embodiments, the UGT exhibits at least a 1.3-fold increase in activity (e.g., specific activity) relative to wildtype UGT94-289-1 (SEQ ID NO: 109). In some embodiments, the UGT comprises an amino acid substitution at an amino acid residue located in a structural motif corresponding to a structural motif in wild-type UGT94-289-1 (SEQ ID NO: 109) selected from: loop 6, alpha helix 3, loop 11, alpha helix 6, loop 12, and alpha helix 7. In some embodiments, the UGT is capable of catalyzing conversion of: Mogrol to MIA1; Mogrol to MIE1; MIA1 to MIIA1; MIE1 to MIIE; MIIA1 to MIIIA1; MIA1 to MIIE; MIIA1 to MIII; MIIIA1 to siamenoside I; MIIE to MIII; MIII to siamenoside I; MIIE to MIIIE; and/or MIIIE to siamenoside I. In some embodiments, the UGT is capable of: glycosylation of mogrol at C24; glycosylation of mogroside at C3; branching glycosylation of mogroside at C3; or branching glycosylation of mogroside C24. In some embodiments, the host cell further comprises a heterologous polynucleotide encoding a CDS enzyme.


Further aspects of the invention relate to a host cell that comprises a heterologous polynucleotide encoding a UGT, wherein the UGT comprises an amino acid substitution at a residue corresponding to N143 or L374 of wild-type UGT94-289-1 (SEQ ID NO: 109), wherein the host cell produces in the presence of at least one mogroside precursor at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% more of one or more mogrosides relative to a host cell that comprises a heterologous polynucleotide encoding wild-type UGT94-289-1 (SEQ ID NO: 109).


In some embodiments, the UGT exhibits at least a 1.3-fold increase in activity (e.g., specific activity) relative to wildtype UGT94-289-1 (SEQ ID NO: 109). In some embodiments, the UGT comprises an amino acid substitution at an amino acid residue located in a structural motif of the UGT corresponding to a structural motif in wild-type UGT94-289-1 (SEQ ID NO: 109) selected from: loop 6, alpha helix 3, loop 11, alpha helix 6, loop 12, and alpha helix 7. In some embodiments, the UGT is capable of catalyzing conversion of: Mogrol to MIA1; Mogrol to MIE1; MIA1 to MIIA1; MIE1 to MIIE; MIIA1 to MIIIA1; MIA1 to MIIE; MIIA1 to MIII; MIIIA1 to siamenoside I; MIIE to MIII; MIII to siamenoside I; MIIE to MIIIE; and/or MIIIE to siamenoside I. In some embodiments, the UGT is capable of: glycosylation of mogrol at C24; glycosylation of mogroside at C3; branching glycosylation of mogroside at C3; or branching glycosylation of mogroside C24. In some embodiments, the host cell further comprises a heterologous polynucleotide encoding a CDS enzyme.


Further aspects of the invention relate to a host cell that comprises a heterologous polynucleotide encoding a UGT, wherein the UGT comprises an amino acid substitution at an amino acid residue located in a structural motif corresponding to a structural motif of wild-type UGT94-289-1 (SEQ ID NO: 109) selected from: loop 8; beta sheet 5; loop 10; alpha helix 5; loop 11; loop 2; alpha helix 6; loop 12; alpha helix 1; alpha helix 7; loop 18; alpha helix 14; loop 26; alpha helix 2; loop 6; and alpha helix 3; wherein the host cell produces in the presence of at least one mogroside precursor at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% more of one or more mogrosides relative to a host cell that comprises a heterologous polynucleotide encoding a UGT that does not comprise the amino acid substitution.


In some embodiments, the UGT exhibits at least a 1.3-fold increase in activity (e.g., specific activity) relative to wildtype UGT94-289-1 (SEQ ID NO: 109). In some embodiments, the UGT is capable of catalyzing conversion of: Mogrol to MIA1; Mogrol to MIE1; MIA1 to MIIA1; MIE1 to MIIE; MIIA1 to MIIIA1; MIA1 to MIIE; MIIA1 to MIII; MIIIA1 to siamenoside I; MIIE to MIII; MIII to siamenoside I; MIIE to MIIIE; and/or MIIIE to siamenoside I. In some embodiments, the UGT is capable of: glycosylation of mogrol at C24; glycosylation of mogroside at C3; branching glycosylation of mogroside at C3; or branching glycosylation of mogroside C24. In some embodiments, the host cell further comprises a heterologous polynucleotide encoding a CDS enzyme.


Further aspects of the invention relate to a host cell that comprises a heterologous polynucleotide encoding a UGT, wherein the UGT comprises an amino acid substitution at an amino acid residue that is within 7 angstrom of a catalytic dyad corresponding to H21/D122 of wildtype UGT94-289-1 (SEQ ID NO: 109), wherein the UGT exhibits at least a 1.3-fold increase in activity (e.g., specific activity) relative to the same UGT not comprising the amino acid substitution.


Further aspects of the invention relate to host cells that comprises a heterologous polynucleotide encoding a circularly permutated UDP-glycosyltransferase (UGT), wherein the circularly permutated UGT comprises: (a) a catalytic dyad; and (b) a cofactor binding site; wherein the catalytic dyad is located C-terminal to the cofactor-binding site, and wherein the host cell produces in the presence of at least one mogroside precursor at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% more of one or more mogrosides relative to a control host cell that comprises a heterologous polynucleotide encoding wild-type UGT94-289-1 (SEQ ID NO: 109).


In some embodiments, a circularly permutated UGT comprises a sequence that is at least 90% identical to a sequence within Table 6.


In some embodiments, a UGT described in this application comprises a sequence that is at least 90% identical to a sequence within Table 3 or Table 7.


In some embodiments, the UGT comprises an amino acid substitution at an amino acid residue located in a structural motif corresponding to a structural motif in wild-type UGT94-289-1 (SEQ ID NO: 109) selected from: loop 6, alpha helix 3, loop 11, alpha helix 6, loop 12, and alpha helix 7.


In some embodiments, the UGT exhibits at least a 1.3-fold increase in activity (e.g., specific activity) relative to wildtype UGT94-289-1 (SEQ ID NO: 109). In some embodiments, the host cell produces in the presence of at least one mogroside precursor at least 40%, 50%, 60%, 70%, 80%, 90%, or 100% more of one or more mogrosides relative to a host cell that comprises a heterologous polynucleotide encoding a UGT that does not comprise the amino acid substitution.


In some embodiments, the UGT is capable of catalyzing conversion of: Mogrol to MIA1; Mogrol to MIE1; MIA1 to MIIA1; MIE1 to MIIE; MIIA1 to MIIIA1; MIA1 to MIIE; MIIA1 to MIII; MIIIA1 to siamenoside I; MIIE to MIII; MIII to siamenoside I; MIIE to MIIIE; and/or MIIIE to siamenoside I. In some embodiments, the UGT is capable of: glycosylation of mogrol at C24; glycosylation of mogroside at C3; branching glycosylation of mogroside at C3; or branching glycosylation of mogroside C24. In some embodiments, the host cell further comprises a heterologous polynucleotide encoding a CDS enzyme.


In some embodiments, the specific activity of the UGT is at least 1 mmol glycosylated mogroside target produced per gram of enzyme per hour.


Further aspects of the invention relate to a host cell that comprises a heterologous polynucleotide encoding a UGT, wherein the UGT comprises an amino acid substitution at an amino acid residue corresponding to the amino acid residue in wild-type UGT94-289-1 (SEQ ID NO: 109) selected from: H83; T84; T85; N86; P89; L92; Y179; S180; A181; G184; A185; V186; T187; K189; H191; K192; G194; E195; and A198.


Further aspects of the invention relate to a host cell that comprises a heterologous polynucleotide encoding a UGT, wherein the UGT comprises an amino acid substitution at an amino acid residue corresponding to the amino acid residue in wild-type UGT94-289-1 (SEQ ID NO: 109) selected from: G18; Y19; S123; N47; F124; N143, T144; T145; V149; F276; N355; H373 and L374.


In some embodiments, the UGT is capable of catalyzing conversion of: Mogrol to MIA1; Mogrol to MIE1; MIA1 to MIIA1; MIE1 to MIIE; MIIA1 to MIIIA1; MIA1 to MIIE; MIIA1 to MIII; MIIIA1 to siamenoside I; MIIE to MIII; MIII to siamenoside I; MIIE to MIIIE; and/or MIIIE to siamenoside I. In some embodiments, the UGT is capable of: glycosylation of mogrol at C24; glycosylation of mogroside at C3; branching glycosylation of mogroside at C3; or branching glycosylation of mogroside C24. In some embodiments, the UGT exhibits at least a 1.3-fold increase in activity (e.g., specific activity) relative to wildtype UGT94-289-1 (SEQ ID NO: 109). In some embodiments, the host cell produces in the presence of at least one mogroside precursor at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% more of one or more mogrosides relative to a host cell that comprises a heterologous polynucleotide encoding wild-type UGT94-289-1 (SEQ ID NO: 109).


In some embodiments, Y179 is mutated to glutamate, phenylalanine, histidine, isoleucine, lysine, leucine, valine, or tryptophan; S180 is mutated to alanine or valine; A181 is mutated to lysine or threonine; G184 is mutated to alanine, cysteine, aspartate, glutamate, phenylalanine, histidine, isoleucine, lysine, methionine, asparagine, proline, glutamine, arginine, serine, threonine, or tyrosine; A185 is mutated to cysteine, aspartate, glutamate, glycine, lysine, leucine, methionine, asparagine, proline, glutamine, threonine, tryptophan or tyrosine; V186 is mutated to alanine, cysteine, aspartate, glutamate, glycine, isoleucine, lysine, leucine, methionine, asparagine, proline, glutamine, arginine, threonine, tryptophan, or tyrosine; T187 is mutated to alanine, cysteine, aspartate, glutamate, glycine, histidine, isoleucine, lysine, leucine, asparagine, proline, arginine, serine, valine, tryptophan, or tyrosine; K189 is mutated to alanine, cysteine, aspartate, glutamate, phenylalanine, glycine, histidine, isoleucine, leucine, methionine, proline, glutamine, arginine, serine, threonine, valine, tryptophan, or tyrosine; H191 is mutated to alanine, cysteine, aspartate, glutamate, glycine, lysine, methionine, proline, glutamine, serine, threonine, valine, tryptophan, or tyrosine; K192 is mutated to cysteine or phenylalanine; G194 is mutated to aspartate, leucine, methionine, asparagine, proline, serine, or tryptophan; E195 is mutated to alanine, isoleucine, lysine, leucine, asparagine, glutamine, serine, threonine, or tyrosine; A198 is mutated to cysteine, aspartate, glutamate, phenylalanine, histidine, isoleucine, lysine, leucine, methionine, asparagine, proline, glutamine, arginine, serine, threonine, valine, or tyrosine; H83 is mutated to glutamine or tryptophan; T84 is mutated to tyrosine; T85 is mutated to glycine, lysine, proline, serine, or tyrosine; N86 is mutated to alanine, cysteine, glutamate, isoleucine, lysine, leucine, serine, tryptophan, or tyrosine; P89 is mutated to methionine or serine; and/or L92 is mutated to histidine or lysine.


In some embodiments, N143 is mutated to alanine, cysteine, glutamate, isoleucine, leucine, methionine, glutamine, serine, threonine or valine; L374 is mutated to alanine, cysteine, phenylalanine, histidine, methionine, asparagine, glutamine, serine, threonine, valine, tryptophan, or tyrosine; S123 is mutated to alanine, cysteine, glycine or valine; F124 is mutated to tyrosine; T144 is mutated to alanine, cysteine, asparagine or proline; T145 is mutated to alanine, cysteine, glycine, methionine, asparagine, glutamine, or serine; V149 is mutated to cysteine, leucine or methionine; G18 is mutated to serine; Y19 is mutated to phenylalanine, histidine, leucine, or valine; F276 is mutated to cysteine or glutamine; N355 is mutated to glutamine or serine; H373 is mutated to lysine, leucine, methionine, arginine, valine, or tyrosine; and/or N47 is mutated to glycine.


In some embodiments, the host cell further comprises a heterologous polynucleotide encoding a CDS enzyme, a C11 hydroxylase, a cytochrome P450 reductase, an epoxide hydrolase (EPH), and/or a squalene epoxidase. In some embodiments, the heterologous polynucleotide encoding the CDS is at least 90% identical to SEQ ID NOs: 3, 9, or 12. In some embodiments, the CDS is at least 90% identical to SEQ ID NOs: 43, 49, or 52.


In some embodiments, the activity (e.g., specific activity) of the UGT is at least 1 mmol glycosylated mogroside target produced per gram of enzyme per hour. In some embodiments, the cell is a yeast cell, a plant cell, or a bacterial cell. In some embodiments, the cell is a Saccharomyces cerevisiae (S. cerevisiae) cell. In some embodiments, the cell is an Escherichia coli (E. coli) cell.


Further aspects of the invention relate to methods of producing a mogroside comprising culturing any of the host cells described in this application with at least one mogroside precursor. In some embodiments, the mogroside precursor is selected from mogrol, MIA1, MIIA1, MIIIA1, MIIE, MIII, and MIIIE. In some embodiments, the mogroside that is produced is selected from MIA1, MIIA1, MIIIA1, MIIE, MIII, siamenoside, and MIIIE.


Further aspects of the invention relate to a host cell that comprises a heterologous polynucleotide encoding a CDS enzyme, wherein the CDS enzyme comprises an amino acid sequence that is at least 90% identical to a sequence selected from the sequences within Table 2 and wherein the host cell produces at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% more cucurbitadienol compound compared to the same host cell that does not express the heterologous gene.


In some embodiments, the cucurbitadienol compound is 24-25 epoxy-cucurbitadienol or cucurbitadienol. In some embodiments, the CDS enzyme comprises a leucine at the amino acid residue corresponding to the amino acid residue at position 123 of SEQ ID NO: 73. In some embodiments, the CDS is capable of converting an oxidosqualene to the cucurbitadienol compound. In some embodiments, the oxidosqualene is 2-3-oxidosqualene or 2,3; 22,23-diepoxysqualene. In some embodiments, the CDS enzyme comprises a substrate channel and an active-site cavity.


In some embodiments, the host cell further expresses a heterologous gene encoding a C11 hydroxylase enzyme, a cytochrome P450 reductase enzyme, an epoxide hydrolase (EPH) enzyme, and/or a squalene epoxidase enzyme.


Further aspects of the invention relate to a method of producing a cucurbitadienol compound, comprising contacting a host cell described in this application with an oxidosqualene, thereby producing the cucurbitadienol compound. In some embodiments, the cucurbitadienol compound is 24-25 epoxy-cucurbitadienol or cucurbitadienol. In some embodiments, the oxidosqualene is 2-3-oxidosqualene or 2,3; 22,23-diepoxysqualene. In some embodiments, the method further comprises isolating the cucurbitadienol compound.


Further aspects of the invention relate to a method of producing mogrol or a mogroside, comprising contacting a host cell described in this application with an oxidosqualene, thereby producing the mogrol or mogroside. Further aspects of the invention relate to a method of producing a mogroside comprising culturing a host cell described in this application with at least one mogroside precursor.


Further aspects of the invention relate to host cells that comprise a heterologous polynucleotide encoding a cucurbitadienol synthase (CDS) enzyme, wherein the CDS comprises: a) the motif GX1WASDLGGP (SEQ ID NO: 331), wherein X1 is N or H; b) the motif DX1GWL (SEQ ID NO: 332), wherein X1 is H or Q; and/or c) the motif CWGVCFTYAGW (SEQ ID NO: 333), wherein the CDS does not comprise the sequence of S. grosvenorii CDS (SEQ ID NO: 73); and wherein the host cell produces at least 10%, 20%, or 30% more cucurbitadienol compound relative to a control, wherein the control is a host cell that expresses S. grosvenorii CDS, encoded by a polynucleotide corresponding to SEQ ID NO:33.


In some embodiments, the motif GX1WASDLGGP (SEQ ID NO: 331) is located at residues in the CDS corresponding to residues 117-126 in SEQ ID NO: 73; the motif DX1GWL (SEQ ID NO: 332) is located at residues in the CDS corresponding to residues 479-483 in SEQ ID NO: 73, and/or the motif CWGVCFTYAGW (SEQ ID NO: 333) is located at residues in the CDS corresponding to residues 612-622 in SEQ ID NO: 73.


Further aspects of the invention relate to host cells that comprises a heterologous polynucleotide encoding a cucurbitadienol synthase (CDS) enzyme, wherein the CDS comprises: a) the motif GHWASDLGGP (SEQ ID NO: 334); and/or b) the motif DQGWL (SEQ ID NO: 335).


In some embodiments, the motif GHWASDLGGP (SEQ ID NO: 334) is located at residues in the CDS corresponding to residues 117-126 in SEQ ID NO: 73; and/or the motif DQGWL (SEQ ID NO: 335) is located at residues in the CDS corresponding to residues 479-483 in SEQ ID NO: 73.


Further aspects of the invention relate to host cells that comprise a heterologous polynucleotide encoding a cucurbitadienol synthase (CDS) enzyme, wherein the CDS comprises: a) the motif GHWANDLGGP (SEQ ID NO: 336); b) the motif DQGWL (SEQ ID NO: 335); and/or c) the motif CWGVCYTYAGW (SEQ ID NO: 337).


In some embodiments, the motif GHWANDLGGP (SEQ ID NO: 336) is located at residues in the CDS corresponding to residues 117-126 in SEQ ID NO: 73; the motif DQGWL (SEQ ID NO: 335) is located at residues in the CDS corresponding to residues 479-483 in SEQ ID NO: 73; and/or the motif CWGVCYTYAGW (SEQ ID NO: 337) is located at residues in the CDS corresponding to residues 612-622 in SEQ ID NO: 73.


In some embodiments, the heterologous polynucleotide is at least 90% identical to SEQ ID NOs: 3, 9, or 12. In some embodiments, the CDS is at least 90% identical to SEQ ID NOs: 43, 49, or 52. In some embodiments, the heterologous polynucleotide is at least 90% identical to SEQ ID NO: 3. In some embodiments, the CDS is at least 90% identical to SEQ ID NOs: 43.


Further aspects of the invention relate to host cells that comprise a heterologous polynucleotide encoding a cucurbitadienol synthase (CDS) enzyme, wherein the heterologous polynucleotide sequence is at least 90% identical to SEQ ID NO: 3 and/or the amino acid sequence of the CDS encoded by the heterologous polynucleotide is at least 90% identical to SEQ ID NO: 43, and wherein the host cell produces a cucurbitadienol compound.


In some embodiments, the cucurbitadienol compound is 24-25 epoxy-cucurbitadienol or cucurbitadienol. In some embodiments, the CDS comprises a leucine at the amino acid residue corresponding to the amino acid residue at position 123 of SEQ ID NO: 73. In some embodiments, the CDS is capable of converting an oxidosqualene to the cucurbitadienol compound. In some embodiments, the oxidosqualene is 2-3-oxidosqualene or 2,3; 22,23-diepoxysqualene. In some embodiments, the CDS enzyme comprises a substrate channel and an active-site cavity.


In some embodiments, the host cell further comprises aone or more heterologous polynucleotides encoding a UDP-glycosyltransferase (UGT), a C11 hydroxylase, a cytochrome P450 reductase, an epoxide hydrolase (EPH), and/or a squalene epoxidase.


Further aspects of the invention relate to methods of producing a cucurbitadienol compound, comprising contacting any of the host cells described in this application with an oxidosqualene, thereby producing the cucurbitadienol compound. In some embodiments, the cucurbitadienol compound is 24-25 epoxy-cucurbitadienol or cucurbitadienol. In some embodiments, the oxidosqualene is 2-3-oxidosqualene or 2,3; 22,23-diepoxysqualene. In some embodiments, the method further comprises isolating the cucurbitadienol compound. In some embodiments, the host cell is a yeast cell, a plant cell, or a bacterial cell. In some embodiments, the host cell is a Saccharomyces cerevisiae cell. In some embodiments, the host cell is an E. coli cell.


Each of the limitations of the invention can encompass various embodiments of the invention. It is, therefore, anticipated that each of the limitations of the invention involving any one element or combinations of elements can be included in each aspect of the invention. This invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.





BRIEF DESCRIPTION OF DRAWINGS

The accompanying drawings are not intended to be drawn to scale. The drawings are illustrative only and are not required for enablement of the disclosure. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:



FIGS. 1A-1D include schematic overviews of putative mogrol biosynthesis pathways. SQS indicates squalene synthase, EPD indicates epoxidase, P450 indicates C11 hydroxylase, EPH indicates epoxide hydrolase, and CDS indicates cucurbitadienol synthase. FIG. 1A and FIG. 1B show putative mogrol biosynthesis pathways. FIG. 1C shows non-limiting examples of primary UGT activity. FIG. 1D shows non-limiting examples of secondary UGT activity.



FIG. 2 is a graph showing liquid chromatography-mass spectrometry (LC-MS) profiles of mogrol, mogroside I-A1, mogroside I-E1, mogroside II-A1, mogroside II-A2, mogroside II-E, mogroside III-A1, mogroside III-E, mogroside IV, and siamenoside I. An 8 minute LC-MS method was used to distinguish between all these mogroside standards.



FIGS. 3A-3B include a series of graphs showing production of mogroside I-A1 (FIG. 3A) and siamenoside I (FIG. 3B) from a UGT library screened against mogroside substrates. Two biological replicates of each strain were screened.



FIGS. 4A-4B include a series of graphs showing production of mogroside I-A1 from mogrol (FIG. 4A) and siamenoside I from mogroside III-A1 (FIG. 4B) in a secondary screen of hit strains on individual substrates. Two biological replicates with two technical replicates of each were screened for each hit strain.



FIG. 5 is a schematic of a homology model of UGT94-289-1. Catalytic dyad side chains are shown within a box, and positions featuring activity enhancing mutations are highlighted in black.



FIG. 6 is a diagram showing the proximity of the N and C termini of the UGT94-289-1 homology model.



FIG. 7 is a schematic showing circular permutation of a protein. The original N and C termini of the native protein are linked together, either directly or with a linker sequence. New N and C termini are introduced at another position within the protein sequence to produce sequence/structural variants.



FIG. 8 depicts diagrams showing Position-Specific Scoring Matrix (PSSM) of residues 50-59 of t85024_N143V (top panel) and evaluation of the impact of these potential mutations using the Rosetta energy function (bottom panel). In the bottom panel, the mutated residue is shown as sticks and the surrounding atoms are shown as lines.



FIG. 9 is a schematic depicting a non-limiting example of an alignment between the UGT U73C6 (SEQ ID NO: 103) and UGT94-289-1 (SEQ ID NO: 109). Boxes highlight residues in U73C6 (SEQ ID NO: 103) corresponding to positions 123, 143, and 273 in UGT94-289-1 (SEQ ID NO: 109).



FIG. 10 is a graph showing relative production of M, MI, and MII as compared to MIII, MIV, and MV by UGTs generated by circular permutation.



FIG. 11 is a graph showing relative production of M, MI, and MII as compared to MIII, MIV, and MV by putative UGTs.





DETAILED DESCRIPTION

Mogrosides are widely used as natural sweeteners, for example in beverages. However, de novo synthesis and mogroside extraction from natural sources often involves high production costs and low yield. This application describes host cells that are engineered to efficiently produce mogrol (or 11,24,25-trihydroxy cucurbitadienol), mogrosides, and precursors thereof. Methods include heterologous expression of cucurbitadienol synthase (CDS) enzymes, UDP-glycosyltransferase (UGT) enzymes, C11 hydroxylase enzymes, cytochrome P450 reductase enzymes, epoxide hydrolase (EPH) enzymes, squalene epoxidase (SQE) enzymes, or combinations thereof. This application describes the identification of improved UGT and CDS enzymes for mogrol and mogroside production. Enzymes and host cells described in this application can be used for making mogrol, mogrosides, and precursors thereof.


Synthesis of Mogrol and Mogrosides



FIGS. 1A-1B show putative mogrol synthesis pathways. An early step in the pathway involves conversion of squalene to 2,3-oxidoqualene. As shown in FIG. 1A, 2,3-oxidosqualene can be first cyclized to cucurbitadienol followed by epoxidation to form 24,25-epoxycucurbitadienol, or 2,3-oxidosqualene can be epoxidized to 2,3,22,23-dioxidosqualene and then cyclized to 24,25-epoxycucurbitadienol. Next, the 24,25-epoxycucurbitadienol can be converted to mogrol (an aglycone of mogrosides) following epoxide hydrolysis and then oxidation, or oxidation and then epoxide hydrolysis. As shown in FIG. 1B, 2,3-oxidosqualene can be first cyclized to cucurbitadienol, which is then converted to 11-hydroxycucurbitadienol by a cytochrome P450 C11 hydroxylase. Then, a cytochrome P450 C11 hydroxylase may convert 11-hydroxycucurbitadienol to 11-hydroxy-24,25-epoxycucurbitadienol. 11-hydroxy-24,25-epoxycucurbitadienol may be converted to mogrol by epoxide hydrolase. C11 hydroxylases act in conjunction with cytochrome P450 reductases (not shown in FIGS. 1A-1B).


Mogrol can be distinguished from other cucurbitane triterpenoids by oxygenations at C3, C11, C24, and C25. Glycosylation of mogrol, for example at C3 and/or C24, leads to the formation of mogrosides.


Mogrol precursors include but are not limited to squalene, 2-3-oxidosqualene, 2,3,22,23-dioxidosqualene, cucurbitadienol, 24,25-expoxycucurbitadienol, 11-hydroxycucurbitadienol, 11-hydroxy-24,25-epoxycucurbitadienol, 11-hydroxy-cucurbitadienol, 11-oxo-cucurbitadienol, and 24,25-dihydroxycucurbitadienol. The term “dioxidosqualene” may be used to refer to 2,3,22,23-diepoxy squalene or 2,3,22,23-dioxido squalene. The term “2,3-epoxysqualene” may be used interchangeably with the term “2-3-oxidosqualene.” As used in this application, mogroside precursors include mogrol precursors, mogrol and mogrosides.


Examples of mogrosides include, but are not limited to, mogroside I-A1 (MIA1), mogroside IE (MIE), mogroside II-A1 (MIIA1), mogroside II-A2 (MIIA2), mogroside III-A1 (MIIIA1), mogroside II-E (MIIE), mogroside III (MIII), siamenoside I, mogroside IV, mogroside IVa, isomogroside IV, mogroside III-E (MIIIE), mogroside V, and mogroside VI. In some embodiments, the mogroside produced is siamenoside I, which may be referred to as Siam. In some embodiments, the mogroside produced is MIIIE.


In other embodiments, a mogroside is a compound of Formula 1:




embedded image


In some embodiments, the methods described in this application may be used to produce any of the compounds described in and incorporated by reference from US 2019/0071705, including compounds 1-20 as disclosed in US 2019/0071705. In some embodiments, the methods described in this application may be used to produce variants of any of the compounds described in and incorporated by reference from US 2019/0071705, including variants of compounds 1-20 as disclosed in US 2019/0071705. For example, a variant of a compound described in US 2019/0071705 can comprise a substitution of one or more alpha-glucosyl linkages in a compound described in US 2019/0071705 with one or more beta-glucosyl linkages. In some embodiments, a variant of a compound described in US 2019/0071705 comprises a substitution of one or more beta-glucosyl linkages in a compound described in US 2019/0071705 with one or more alpha-glucosyl linkages. In some embodiments, a variant of a compound described in US 2019/0071705 is a compound of Formula 1 shown above.


Cucurbitadienol Synthase (CDS) Enzymes


Aspects of the present disclosure provide cucurbitadienol synthase (CDS) enzymes, which may be useful, for example, in the production of a cucurbitadienol compound, such as 24-25 epoxy-cucurbitadienol or cucurbitadienol. CDSs are capable of catalyzing the formation of cucurbitadienol compounds, such as 24-25 epoxy-cucurbitadienol or cucurbitadienol from oxidosqualene (e.g., 2-3-oxidosqualene or 2,3; 22,23-diepoxysqualene).


In some embodiments, CDS enzymes have a leucine residue corresponding to position 123 of SEQ ID NO: 74 that distinguishes them from other oxidosqualene cyclases, as discussed in Takase et al. Org. Biomol. Chem., 2015, 13, 7331-7336, which is incorporated by reference in its entirety.


CDSs of the present disclosure may comprise a sequence that is at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical, including all values in between, to a nucleic acid or amino acid sequence in Table 2 or to a sequence selected from SEQ ID NOs: 1-80.


In some embodiments a CDS enzyme corresponds to SEQ ID NO: 43, SEQ ID NO: 52, or SEQ ID NO: 49.


In some embodiments, a polynucleotide sequence encoding a CDS enzyme may be re-coded for expression in a particular host cell, including S. cerevisiae. In some embodiments, a re-coded polynucleotide sequence encoding a CDS enzyme corresponds to SEQ ID NO: 34.


In some embodiments, a polynucleotide sequence encoding a CDS is at least 90% identical to SEQ ID NOs: 3, 9, or 12. In some embodiments, a CDS is at least 90% identical to SEQ ID NOs: 43, 49, or 52.


In some embodiments, a CDS of the present disclosure is capable of using oxidosqualene (e.g., 2,3-oxidosqualene or 2,3; 22,23-diepoxysqualene) as a substrate. In some embodiments, a CDS of the present disclosure is capable of producing cucurbitadienol compounds (e.g., 24-25 epoxy-cucurbitadienol or cucurbitadienol). In some embodiments, a CDS of the present disclosure catalyzes the formation of cucurbitadienol compounds (e.g., 24-25 epoxy-cucurbitadienol or cucurbitadienol) from oxidosqualene (e.g., 2-3-oxidosqualene or 2,3; 22,23-diepoxysqualene).


It should be appreciated that activity of a CDS can be measured by any means known to one of ordinary skill in the art. In some embodiments, the activity of a CDS may be measured as the normalized peak area of cucurbitadienol produced. In some embodiments, this activity is measured in arbitrary units. In some embodiments, the activity, such as specific activity, of a CDS of the present disclosure is at least 1.1 fold (e.g., at least 1.3 fold, at least 1.5 fold, at least 1.7 fold, at least 1.9 fold, at least 2 fold, at least 2.5 fold, at least 3 fold, at least 4 fold, at least 5 fold, at least 10 fold, at least 20 fold, at least 30 fold, at least 40 fold, at least 50 fold, or at least 100 fold, including all values in between) greater than that of a control CDS.


It should be appreciated that one of ordinary skill in the art would be able to characterize a protein as a CDS enzyme based on structural and/or functional information associated with the protein. For example, in some embodiments, a protein can be characterized as a CDS enzyme based on its function, such as the ability to produce cucurbitadienol compounds (e.g., 24-25 epoxy-cucurbitadienol or cucurbitadienol) using oxidosqualene (e.g., 2,3-oxidosqualene or 2,3; 22,23-diepoxysqualene) as a substrate. In some embodiments, a protein can be characterized, at least in part, as a CDS enzyme based on the presence of a leucine residue at a position corresponding to position 123 of SEQ ID NO: 73.


In some embodiments, a CDS comprises the motif GX1WASDLGGP (SEQ ID NO: 331), wherein X1 is N or H. In some embodiments, the motif GX1WASDLGGP (SEQ ID NO: 331) is located in the CDS at residues corresponding to positions 117-126 in SEQ ID NO: 73.


In some embodiments, a CDS comprises the motif DX1GWL (SEQ ID NO: 332), wherein X1 is H or Q. In some embodiments, the motif DX1GWL (SEQ ID NO: 332) is located in the CDS at residues corresponding to positions 479-483 in SEQ ID NO: 73.


In some embodiments, a CDS comprises the motif CWGVCFTYAGW (SEQ ID NO: 333). In some embodiments, the motif CWGVCFTYAGW (SEQ ID NO: 333) is located in the CDS at residues corresponding to positions 612-622 in SEQ ID NO: 73.


In some embodiments, a CDS comprises the motif GHWASDLGGP (SEQ ID NO: 334). In some embodiments, the motif GHWASDLGGP (SEQ ID NO: 334) is located in the CDS at residues corresponding to positions 117-126 in SEQ ID NO: 73. In some embodiments, a CDS comprises the motif DQGWL (SEQ ID NO: 335). In some embodiments, the motif DQGWL (SEQ ID NO: 335) is located in the CDS at residues corresponding to positions 479-483 in SEQ ID NO: 73.


In some embodiments, a CDS comprises the motif GHWASDLGGP (SEQ ID NO: 334), the motif DQGWL (SEQ ID NO: 335), and/or the motif CWGVCFTYAGW (SEQ ID NO: 333).


In some embodiments, a CDS comprises a leucine at a residue corresponding to position 123 in SEQ ID NO: 73. In some embodiments, a CDS comprises a leucine at a residue corresponding to position 483 in SEQ ID NO: 73. In some embodiments, a CDS comprises a cysteine at a residue corresponding to position 612 in SEQ ID NO: 73, a glycine at a residue corresponding to position 614 in SEQ ID NO: 73, an alanine at a residue corresponding to position 620 in SEQ ID NO: 73, and/or a glycine at a residue corresponding to position 621 in SEQ ID NO: 73. In some embodiments, a CDS comprises a leucine at a residue corresponding to position 123 in SEQ ID NO: 73, a leucine at a residue corresponding to position 483 in SEQ ID NO: 73, a cysteine at a residue corresponding to position 612 in SEQ ID NO: 73, a glycine at a residue corresponding to position 614 in SEQ ID NO: 73, an alanine at a residue corresponding to position 620 in SEQ ID NO: 73, and/or a glycine at a residue corresponding to position 621 in SEQ ID NO: 73.


In some embodiments, a CDS comprises the motif GHWANDLGGP (SEQ ID NO: 336). In some embodiments, the motif GHWANDLGGP (SEQ ID NO: 336) is located in the CDS at residues corresponding to positions 117-126 in SEQ ID NO: 73.


In some embodiments, a CDS comprises the motif DX1GWL (SEQ ID NO: 332). In some embodiments, the motif DX1GWL (SEQ ID NO: 332) is located in the CDS at residues corresponding to positions 479-483 in SEQ ID NO: 73.


In some embodiments, a CDS comprises the motif CWGVCYTYAGW (SEQ ID NO: 337). In some embodiments, the motif CWGVCYTYAGW (SEQ ID NO: 337) is located in the CDS at residues corresponding to positions 612-622 in SEQ ID NO: 73.


In some embodiments, a CDS comprises: the motif GHWANDLGGP (SEQ ID NO: 336), located at residues corresponding to positions 117-126 in SEQ ID NO: 73; the motif DQGWL (SEQ ID NO: 335), located at residues corresponding to positions 479-483 in SEQ ID NO: 73; and/or the motif CWGVCYTYAGW (SEQ ID NO: 337), located at residues corresponding to positions 612-622 in SEQ ID NO: 73.


In some embodiments, a host cell that comprises a heterologous polynucleotide encoding a CDS enzyme produces at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% more cucurbitadienol compound compared to the same host cell that does not express the heterologous gene.


In some embodiments, a host cell that comprises a heterologous polynucleotide encoding a CDS enzyme produces at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% more cucurbitadienol compound relative to a control host cell, wherein the control host cell expresses S. grosvenorii CDS, encoded by a polynucleotide corresponding to SEQ ID NO:33.


Throughout this disclosure, host cells that express any of the heterologous polynucleotides described in this application may be compared to a control host cell. It should be appreciated that a control host cell may have the same genetic background as a host cell that is expressing a specific heterologous polynucleotide sequence, except that the control host cell would not express the same specific heterologous polynucleotide sequence.


In other embodiments, a protein can be characterized as a CDS enzyme based on the percent identity between the protein and a known CDS enzyme. For example, the protein may be at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical, including all values in between, to any of the CDS sequences described in this application or the sequence of any other CDS enzyme. In other embodiments, a protein can be characterized as a CDS enzyme based on the presence of one or more domains in the protein that are associated with CDS enzymes. For example, in certain embodiments, a protein is characterized as a CDS enzyme based on the presence of a substrate channel and/or an active-site cavity characteristic of CDS enzymes known in the art. In some embodiments, the active site cavity comprises a residue that acts a gate to this channel, helping to exclude water from the cavity. In some embodiments, the active-site comprises a residue that acts a proton donor to open the epoxide of the substrate and catalyze the cyclization process.


In other embodiments, a protein can be characterized as a CDS enzyme based on a comparison of the three-dimensional structure of the protein compared to the three-dimensional structure of a known CDS enzyme. It should be appreciated that a CDS enzyme can be a synthetic protein.


UDP-Glycosyltransferases (UGT) Enzymes


Aspects of the present disclosure provide UDP-glycosyltransferase enzymes (UGTs), which may be useful, for example, in the production of a mogroside (e.g., mogroside I-A1 (MIA1), mogroside I-E (MIE), mogroside II-A1 (MIIA1), mogroside II-A2 (MIIA2), mogroside III-A1 (MIIIA1), mogroside II-E (MIIE), mogroside III (MIII), siamenoside I, mogroside III-E (MIIIE), mogroside IV, mogroside IVa, isomogroside IV, mogroside V, or mogroside VI).


As used in this application, a “UGT” refers to an enzyme that is capable of catalyzing the addition of the glycosyl group from a UTP-sugar to a compound (e.g., mogroside or mogrol). A UGT may be a primary and/or a secondary UGT. A “primary” UGT refers to a UGT that is capable of catalyzing the addition of a glycosyl group to a position on a compound that does not comprise a glycosyl group. For example, a primary UGT may be capable of adding a glycosyl group to the C3 and/or C24 position of an isoprenoid substrate (e.g., mogrol). See, e.g., FIG. 1C. A “secondary” UGT refers to a UGT that is capable of catalyzing the addition of a glycosyl group to a position on a compound that already comprises a glycosyl group. See, e.g., FIG. 1D. As a non-limiting example, a secondary UGT may add a glycosyl group to a mogroside I-A1 (MIA1), mogroside I-E (MIE), mogroside II-A1 (MIIA1), mogroside II-A2 (MIIA2), mogroside III-A1 (MIIIA1), mogroside II-E (MIIE), mogroside III (MIII), siamenoside I, mogroside III-E (MIIIE), mogroside IV, mogroside IVa, isomogroside IV, mogroside V, and/or mogroside VI.


Structurally, UGTs often comprise a UDPGT (Prosite: PS00375) domain and a catalytic dyad. As a non-limiting example, one of ordinary skill in the art may identify a catalytic dyad in a UGT by aligning the UGT sequence to UGT94-289-1 (a wildtype UGT sequence from the monk fruit Siraitia grosvenorii) and identifying the two residues in the UGT that correspond to histidine 21 (H21) and aspartate 122 (D122) of UGT94-289-1.


The amino acid sequence for UGT94-289-1 is:









(SEQ ID NO: 109)


MDAQRGHTTTILMFPWLGYGHLSAFLELAKSLSRRNFHIYFCSTSVNLD





AIKPKLPSSSSSDSIQLVELCLPSSPDQLPPHLHTTNALPPHLMPTLHQ





AFSMAAQHFAAILHTLAPHLLIYDSFQPWAPQLASSLNIPAINFNTTGA





SVLTRMLHATHYPSSKFPISEFVLHDYWKAMYSAAGGAVTKKDHKIGET





LANCLHASCSVILINSFRELEEKYMDYLSVLLNKKVVPVGPLVYEPNQD





GEDEGYSSIKNWLDKKEPSSTVFVSFGSEYFPSKEEMEEIAHGLEASEV





HFIWVVRFPQGDNTSAIEDALPKGFLERVGERGMVVKGWAPQAKILKHW





STGGFVSHCGWNSVMESMMFGVPIIGVPMHLDQPFNAGLAEEAGVGVEA





KRDPDGKIQRDEVAKLIKEVVVEKTREDVRKKAREMSEILRSKGEEKMD





EMVAAISLFLKI.






A non-limiting example of a nucleic acid sequence encoding UGT94-289-1 is:









(SEQ ID NO: 93)


atggacgcgcaacgcggacatacgactaccatcctgatgtttccgtggt





tggggtacggccaccttagtgcattcctcgaattagccaagagcttgtc





gcgtaggaactttcatatttatttctgttccacatctgtcaatttagat





gctataaaacccaaactaccatcatcttcaagttccgattctattcagc





ttgtagagttatgcttgccttcctcgccagaccaactacccccacacct





gcatacaactaatgctctacctccacatctaatgcctaccctgcaccag





gccttttcaatggcagctcaacattttgcagctatattacatactttag





caccgcacttgttaatctatgattcgttccagccttgggcgccacaatt





ggccagctctcttaacattcctgctattaattttaataccacgggtgcc





agtgtgctaacaagaatgttacacgcgactcattacccatcttcaaagt





tcccaatctccgaatttgttttacatgattattggaaagcaatgtattc





agcagctggtggtgctgttacaaaaaaggaccataaaataggagaaacc





ttggcaaactgtttacacgcttcttgctcggtaattctgatcaattcat





tcagagagttggaagaaaaatacatggattacttgtctgtcttactaaa





caagaaagttgtgcccgtgggtccgcttgtttatgagccaaaccaagat





ggcgaagacgaaggttatagttcgataaagaattggctcgataaaaagg





agccctcctcaactgtctttgtttccttcgggtccgaatattttccgtc





caaagaagaaatggaagaaattgcccatggcttggaggctagcgaggta





cactttatttgggtcgttagattcccacaaggagacaatacttctgcaa





ttgaagatgcccttcctaagggttttcttgagcgagtgggcgaacgtgg





aatggtggttaagggttgggctcctcaggccaaaattttgaaacattgg





agcacaggcggtttcgtaagtcattgtggatggaatagtgttatggaga





gcatgatgtttggtgtacccataataggtgttccgatgcatttagatca





accatttaatgcagggctcgcggaagaagcaggagtaggggtagaggct





aaaagggaccctgatggtaagatacagagagatgaagtcgctaaactga





tcaaagaagtggttgtcgaaaaaacgcgcgaagatgtcagaaagaaggc





tagggaaatgtctgaaattttacgttcgaaaggtgaggaaaagatggac





gagatggttgcagccattagtctcttcttgaagatataa.






One of ordinary skill in the art would readily recognize how to determine for any UGT enzyme what amino acid residue corresponds to a specific amino acid residue in UGT94-289-1 (SEQ ID NO: 109) by, for example, aligning sequences and/or by comparing secondary or tertiary structures.


In certain embodiments, a UGT of the present disclosure comprises one or more structural motifs corresponding to a structural motif in wild-type UGT94-289-1 (e.g., corresponding to a structural motif that is shown in Table 5). In some embodiments, a UGT comprises structural motifs corresponding to all structural motifs in Table 5. In some embodiments, a UGT comprises a structural motif that corresponds to some but not all structural motifs shown in Table 5. In some embodiments, some structural motifs may diverge by having different lengths or different helicity. For example, a UGT of the present disclosure may comprise extended versions of loops 11, 16, 20, or a combination thereof in UGT94-289-1. A UGT of the present disclosure may comprise loops that have greater helicity than their counterpart in UGT94-289-1 (e.g., loops 11, 16, 20, or a combination thereof in UGT94-289-1).


In some embodiments, a UGT is a circularly permutated version of a reference UGT. In some embodiments, a UGT comprises a sequence that includes at least two motifs from Table 5 in a different order than a reference UGT. For example, if UGT94-289-1 is used as a reference UGT and comprises a first motif that is located C-terminal to a second motif, the first motif may be located N-terminal to the second motif in a circularly permutated UGT.


A UGT may comprise one or more motifs corresponding to one or more motifs selected from Loop 1, Beta Sheet 1, Loop 2, Alpha Helix 1, Loop 3, Beta Sheet 2, Loop 4, Alpha Helix 2, Loop 5, Beta Sheet 3, Loop 6, Alpha Helix 3, Loop 7, Beta Sheet 4, Loop 8, Alpha Helix 4, Loop 9, Beta Sheet 5, Loop 10, Alpha Helix 5, Loop 11, Alpha Helix 6, Loop 12, Alpha Helix 7, Loop 13, Beta Sheet 6, Loop 14, Alpha Helix 8, and Loop 15 from Table 5 located C-terminal to one or more motifs corresponding to one or more motifs selected from Beta Sheet 7, Loop 16, Alpha Helix 9, Loop 17, Beta Sheet 8, Loop 18, Alpha Helix 10, Loop 19, Beta Sheet 9, Alpha Helix 11, Loop 20, Alpha Helix 12, Loop 21, Beta Sheet 10, Loop 22, Alpha Helix 13, Loop 23, Beta Sheet 11, Loop 24, Alpha Helix 14, Loop 25, Beta Sheet 12, Loop 26, Alpha Helix 15, Loop 27, Beta Sheet 13, Loop 28, Alpha Helix 16, Loop 29, Alpha Helix 17, Loop 30, Alpha Helix 18, and Loop 31 in Table 5.


In some embodiments, the N-terminal portion of a UGT comprises a catalytic site, including a catalytic dyad, and/or a substrate-binding site. In some embodiments, the C-terminal portion of a UGT comprises a cofactor-binding site. For example, the N-terminal portion of UGT94-289-1 comprises a catalytic dyad corresponding to residues 21 and 122 of wildtype UGT94-289-1 (e.g., histidine 21 and aspartate acid 122). The C-terminal portion of UGT94-289-1 comprises a cofactor-binding site.


Aspects of the disclosure include UGTs that have been circularly permutated. In some embodiments, in a circularly permutated version of a UGT, the N-terminal portion and the C-terminal portions may be reversed in whole or in part. For example, the C-terminal portion of a circularly permutated UGT may comprise a catalytic site, including a catalytic dyad, and/or a substrate-binding site, while the N-terminal portion may comprise a cofactor-binding site.


In some embodiments, a circularly permutated version of a UGT comprises a heterologous polynucleotide encoding a UGT, wherein the UGT comprises: a catalytic dyad and a cofactor binding site, wherein the catalytic dyad is located C-terminal to the cofactor-binding site.


A circularly permutated UGT encompassed by the disclosure may exhibit different properties from the same UGT that has not undergone circular permutation. In some embodiments, a host cell expressing such a circularly permutated version of a UGT produces in the presence of at least one mogroside precursor at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% more of one or more mogrosides relative to a host cell that comprises a heterologous polynucleotide encoding a reference UGT that is not circularly permutated, such as wild-type UGT94-289-1 (SEQ ID NO: 109). In some embodiments, a host cell expressing such a circularly permutated version of a UGT produces in the presence of at least one mogroside precursor at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% less of one or more mogrosides relative to a host cell that comprises a heterologous polynucleotide encoding a reference UGT that is not circularly permutated, such as wild-type UGT94-289-1 (SEQ ID NO: 109).


In some embodiments, in a circularly permutated version of a UGT, the N-terminal portion of a UGT comprises residues that are usually present in the C-terminal portion of a UGT, such as UGT94-289-1. In some embodiments, in a circularly permutated version of a UGT, the C-terminal portion of a UGT comprises residues that are usually present in the N-terminal portion of a UGT, such as UGT94-289-1.


In some embodiments, the N-terminal portion of a UGT, such as UGT94-289-1, corresponds to approximately residues 2-122, residues 2-123, residues 2-124, residues 2-125, residues 2-126, residues 2-127, residues 2-128, residues 2-129, residues 2-130, residues 2-131, residues 2-132, residues 2-133, residues 2-134, residues 2-135, residues 2-136, residues 2-137, residues 2-138, residues 2-139, residues 2-140, residues 2-141, residues 2-142, residues 2-143, residues 2-144, residues 2-145, residues 2-146, residues 2-147, residues 2-148, residues 2-149, residues 2-150, residues 2-151, residues 2-152, residues 2-153, residues 2-154, residues 2-155, residues 2-156, residues 2-157, residues 2-158, residues 2-159, residues 2-160, residues 2-161, residues 2-162, residues 2-163, residues 2-164, residues 2-165, residues 2-166, residues 2-167, residues 2-168, residues 2-169, residues 2-170, residues 2-171, residues 2-172, residues 2-173, residues 2-174, residues 2-175, residues 2-176, residues 2-177, residues 2-178, residues 2-179, residues 2-180, residues 2-181, residues 2-182, residues 2-183, residues 2-184, residues 2-185, residues 2-186, residues 2-187, residues 2-188, residues 2-189, residues 2-190, residues 2-191, residues 2-192, residues 2-193, residues 2-194, residues 2-195, residues 2-196, residues 2-197, residues 2-198, residues 2-199, residues 2-200, residues 2-201, residues 2-202, residues 2-203, residues 2-204, residues 2-205, residues 2-206, residues 2-207, residues 2-208, residues 2-209, residues 2-210, residues 2-211, residues 2-212, residues 2-213, residues 2-214, residues 2-215, residues 2-216, residues 2-217, residues 2-218, residues 2-219, residues 2-220, residues 2-221, residues 2-222, residues 2-223, residues 2-224, residues 2-225, residues 2-226, residues 2-227, residues 2-228, residues 2-229, residues 2-230, residues 2-231, residues 2-232, residues 2-233, residues 2-234, residues 2-235, residues 2-236, residues 2-237, residues 2-238, residues 2-239, residues 2-240, residues 2-241, residues 2-242, residues 2-243, residues 2-244, residues 2-245, residues 2-246, residues 2-247, residues 2-248, residues 2-249, residues 2-250, residues 2-251, or residues 2-252 of a UGT, such as UGT94-289-1 (SEQ ID NO: 109), or corresponding residues in another UGT.


In some embodiments, the C-terminal domain of a UGT, such as UGT94-289-1, corresponds to approximately residues 123-456, residues 124-456, residues 125-456, residues 126-456, residues 127-456, residues 128-456, residues 129-456, residues 130-456, residues 131-456, residues 132-456, residues 133-456, residues 134-456, residues 135-456, residues 136-456, residues 137-456, residues 138-456, residues 139-456, residues 140-456, residues 141-456, residues 142-456, residues 143-456, residues 144-456, residues 145-456, residues 146-456, residues 147-456, residues 148-456, residues 149-456, residues 150-456, residues 151-456, residues 152-456, residues 153-456, residues 154-456, residues 155-456, residues 156-456, residues 157-456, residues 158-456, residues 159-456, residues 160-456, residues 161-456, residues 162-456, residues 163-456, residues 164-456, residues 165-456, residues 166-456, residues 167-456, residues 168-456, residues 169-456, residues 170-456, residues 171-456, residues 172-456, residues 173-456, residues 174-456, residues 175-456, residues 176-456, residues 177-456, residues 178-456, residues 179-456, residues 180-456, residues 181-456, residues 182-456, residues 183-456, residues 184-456, residues 185-456, residues 186-456, residues 187-456, residues 188-456, residues 189-456, residues 190-456, residues 191-456, residues 192-456, residues 193-456, residues 194-456, residues 195-456, residues 196-456, residues 197-456, residues 198-456, residues 199-456, residues 200-456, residues 201-456, residues 202-456, residues 203-456, residues 204-456, residues 205-456, residues 206-456, residues 207-456, residues 208-456, residues 209-456, residues 210-456, residues 211-456, residues 212-456, residues 213-456, residues 214-456, residues 215-456, residues 216-456, residues 217-456, residues 218-456, residues 219-456, residues 220-456, residues 221-456, residues 222-456, residues 223-456, residues 224-456, residues 225-456, residues 226-456, residues 227-456, residues 228-456, residues 229-456, residues 230-456, residues 231-456, residues 232-456, residues 233-456, residues 234-456, residues 235-456, residues 236-456, residues 237-456, residues 238-456, residues 239-456, residues 240-456, residues 241-456, residues 242-456, residues 243-456, residues 244-456, residues 245-456, residues 246-456, residues 247-456, residues 248-456, residues 249-456, residues 250-456, or residues 251-456 of a UGT, such as UGT94-289-1 (SEQ ID NO: 109), or corresponding residues in another UGT.


In some embodiments, a UGT of the present disclosure comprises a sequence (e.g., nucleic acid or amino acid sequence) that is at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical, including all values in between, to a sequence in Tables 3, 6 or 7, to a sequence selected from SEQ ID NOs: 207-242, SEQ ID NOs: 243-316, SEQ ID NOs: 225-242, SEQ ID NOs: 280-316, SEQ ID NOs: 317-322, SEQ ID NOs: 323-328, or SEQ ID NO: 330 or to any of the UGTs disclosed in this application.


In some embodiments, a UGT of the present disclosure may comprise an amino acid substitution at an amino acid residue corresponding to an amino acid residue in wild-type UGT94-289-1 (SEQ ID NO: 109). For example, an amino acid residue that contains a substitution can be an amino acid that corresponds to an amino acid residue in wild-type UGT94-289-1 (SEQ ID NO: 109) selected from, e.g., S123; F124; N143; T144; T145; V149; Y179; G18; S180; A181; G184; A185; V186; T187; K189; Y19; H191; K192; G194; E195; A198; F276; N355; H373; L374; N47; H83; T84; T85; N86; P89; and/or L92. Non-limiting examples of such amino acid substitutions include: S123 may be mutated to alanine, cysteine, glycine or valine, or to any conservative substitution of alanine, cysteine, glycine or valine; F124 may be mutated to tyrosine or to any conservative substitution of tyrosine; N143 may be mutated to alanine, cysteine, glutamate, isoleucine, leucine, methionine, glutamine, serine, threonine or valine, or to any conservative substitution of alanine, cysteine, glutamate, isoleucine, leucine, methionine, glutamine, serine, threonine or valine; T144 may be mutated to alanine, cysteine, asparagine or proline, or to any conservative substitution of alanine, cysteine, asparagine or proline; T145 may be mutated to alanine, cysteine, glycine, methionine, asparagine, glutamine, or serine, or any conservative substitution of alanine, cysteine, glycine, methionine, asparagine, glutamine, or serine; V149 may be mutated to cysteine, leucine or methionine, or to any conservative substitution of cysteine, leucine or methionine; Y179 may be mutated to glutamate, phenylalanine, histidine, isoleucine, lysine, leucine, valine, or tryptophan, or to any conservative substitution glutamate, phenylalanine, histidine, isoleucine, lysine, leucine, valine, or tryptophan; G18 may be mutated to serine or to any conservative substitution of serine; S180 may be mutated to alanine or valine, or to any conservative substitution of alanine or valine; A181 may be mutated to lysine or threonine, or to any conservative substitution of lysine or threonine; G184 may be mutated to alanine, cysteine, aspartate, glutamate, phenylalanine, histidine, isoleucine, lysine, methionine, asparagine, proline, glutamine, arginine, serine, threonine, or tyrosine, or to any conservative substitution of alanine, cysteine, aspartate, glutamate, phenylalanine, histidine, isoleucine, lysine, methionine, asparagine, proline, glutamine, arginine, serine, threonine, or tyrosine; A185 may be mutated to cysteine, aspartate, glutamate, glycine, lysine, leucine, methionine, asparagine, proline, glutamine, threonine, tryptophan or tyrosine, or to any conservative substitution of cysteine, aspartate, glutamate, glycine, lysine, leucine, methionine, asparagine, proline, glutamine, threonine, tryptophan or tyrosine; V186 may be mutated to alanine, cysteine, aspartate, glutamate, glycine, isoleucine, lysine, leucine, methionine, asparagine, proline, glutamine, arginine, threonine, tryptophan, or tyrosine, or to any conservative substitution of alanine, cysteine, aspartate, glutamate, glycine, isoleucine, lysine, leucine, methionine, asparagine, proline, glutamine, arginine, threonine, tryptophan, or tyrosine; T187 may be mutated to alanine, cysteine, aspartate, glutamate, glycine, histidine, isoleucine, lysine, leucine, asparagine, proline, arginine, serine, valine, tryptophan, or tyrosine, or to any conservative substitution of alanine, cysteine, aspartate, glutamate, glycine, histidine, isoleucine, lysine, leucine, asparagine, proline, arginine, serine, valine, tryptophan, or tyrosine; K189 may be mutated to alanine, cysteine, aspartate, glutamate, phenylalanine, glycine, histidine, isoleucine, leucine, methionine, proline, glutamine, arginine, serine, threonine, valine, tryptophan, or tyrosine, or to any conservative substitution thereof of alanine, cysteine, aspartate, glutamate, phenylalanine, glycine, histidine, isoleucine, leucine, methionine, proline, glutamine, arginine, serine, threonine, valine, tryptophan, or tyrosine; Y19 may be mutated to phenylalanine, histidine, leucine, or valine, or to any conservative substitution of phenylalanine, histidine, leucine, or valine; H191 may be mutated to alanine, cysteine, aspartate, glutamate, glycine, lysine, methionine, proline, glutamine, serine, threonine, valine, tryptophan, or tyrosine, or to any conservative substitution of mutated to alanine, cysteine, aspartate, glutamate, glycine, lysine, methionine, proline, glutamine, serine, threonine, valine, tryptophan, or tyrosine; K192 may be mutated to cysteine or phenylalanine, or to any conservative substitution of cysteine or phenylalanine; G194 may be mutated to aspartate, leucine, methionine, asparagine, proline, serine, or tryptophan, or to any conservative substitution of aspartate, leucine, methionine, asparagine, proline, serine, or tryptophan; E195 may be mutated to alanine, isoleucine, lysine, leucine, asparagine, glutamine, serine, threonine, or tyrosine, or to any conservative substitution of alanine, isoleucine, lysine, leucine, asparagine, glutamine, serine, threonine, or tyrosine; A198 may be mutated to cysteine, aspartate, glutamate, phenylalanine, histidine, isoleucine, lysine, leucine, methionine, asparagine, proline, glutamine, arginine, serine, threonine, valine, or tyrosine, or to any conservative substitution of cysteine, aspartate, glutamate, phenylalanine, histidine, isoleucine, lysine, leucine, methionine, asparagine, proline, glutamine, arginine, serine, threonine, valine, or tyrosine; F276 may be mutated to cysteine or glutamine, or to any conservative substitution of cysteine or glutamine; N355 may be mutated to glutamine or serine, or any conservative substitution thereof; H373 may be mutated to lysine, leucine, methionine, arginine, valine, or tyrosine, or to any conservative substitution of lysine, leucine, methionine, arginine, valine, or tyrosine; L374 may be mutated to alanine, cysteine, phenylalanine, histidine, methionine, asparagine, glutamine, serine, threonine, valine, tryptophan, or tyrosine, or to any conservative substitution of alanine, cysteine, phenylalanine, histidine, methionine, asparagine, glutamine, serine, threonine, valine, tryptophan, or tyrosine; N47 may be mutated to glycine or to any conservative substitution of glycine; H83 may be mutated to glutamine or tryptophan, or to any conservative substitution of glutamine or tryptophan; T84 may be mutated to tyrosine or to any conservative substitution of tyrosine; T85 may be mutated to glycine, lysine, proline, serine, or tyrosine, or to any conservative substitution of glycine, lysine, proline, serine, or tyrosine; N86 may be mutated to alanine, cysteine, glutamate, isoleucine, lysine, leucine, serine, tryptophan, or tyrosine, or to any conservative substitution of alanine, cysteine, glutamate, isoleucine, lysine, leucine, serine, tryptophan, or tyrosine; P89 may be mutated to methionine or serine or to any conservative substitution of methionine or serine; and/or L92 may be mutated to histidine or lysine or to any conservative substitution of histidine or lysine.


One of ordinary skill in the art would readily recognize how to determine for any UGT enzyme what amino acid residue corresponds to a specific amino acid residue in UGT94-289-1 (SEQ ID NO: 109) by, for example, aligning sequences and/or by comparing secondary structures. As a non-limiting example, a sequence alignment (e.g., conducted using Clustal Omega, see e.g., Larkin et al., Bioinformatics. 2007 Nov. 1; 23(21):2947-8) is provided in FIG. 9 between UGT94-289-1 (SEQ ID NO: 109) and U73C6 (SEQ ID NO: 103). For example, in FIG. 9, the residue in U73C6 (SEQ ID NO: 103) corresponding to position 123 in UGT94-289-1 (SEQ ID NO: 109) is methionine (M). As another non-limiting example, the residue in U73C6 (SEQ ID NO: 103) corresponding to position 143 in UGT94-289-1 (SEQ ID NO: 109) is histidine (H) (FIG. 9). As another non-limiting example, the residue in U73C6 (SEQ ID NO: 103) corresponding to position 273 in UGT94-289-1 (SEQ ID NO: 109) is phenylalanine (F) (FIG. 9).


In some embodiments, a UGT comprises an amino acid substitution corresponding to the amino acid substitutions in UGT94-289-1 set forth in Table 4.


A UGT of the present disclosure can comprise a conservative amino acid substitution and/or a non-conservative amino acid substitution. In some embodiments, a UGT of the present disclosure comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more than 10 conservative amino acid substitution(s). In some embodiments, a UGT of the present disclosure comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more than 10 non-conservative amino acid substitutions. In some embodiments, a conservative or non-conservative amino acid substitution is not located in a conserved region of a UGT protein. In some embodiments, a conservative or non-conservative amino acid substitution is not located in a region corresponding to: residues 83 to 92; residues 179 to 198; residue N143; residue L374; residue H21; or residue D122 of wild-type UGT94-289-1. One of ordinary skill in the art would readily be able to test a UGT that comprises a conservative and/or non-conservative substitution to determine whether the conservative and/or non-conservative substitution impacts the activity or function of the UGT.


In some embodiments, a UGT enzyme contains an amino acid substitution located within 10 angstrom, 9 angstrom 8 angstrom, 7 angstrom, 6 angstrom, 5 angstrom, 4 angstrom, 3 angstrom, 2 angstrom, or within 1 angstrom (including all values in between) of a catalytic dyad. The catalytic dyad may correspond to residues 21 and 122 of wildtype UGT94-289-1 (e.g., histidine 21 and aspartate acid 122). It should be appreciated that one of ordinary skill in the art would readily recognize how to determine to corresponding location of the catalytic dyad in any UGT enzyme, for example, by aligning the sequence and/or by comparing the secondary structure with UGT94-289-1 (SEQ ID NO: 109).


In some embodiments, a UGT enzyme contains an amino acid substitution at an amino acid residue located in one or more structural motifs of the UGT. Non-limiting examples of secondary structures in UGTs, such as UGT94-289-1 (SEQ ID NO: 109), include: the loop between beta sheet 4 and alpha helix 5; beta sheet 5; the loop between beta sheet 5 and alpha helix 6; alpha helix 6; the loop between alpha helix 6 & 7; the loop between beta sheet 1 & alpha helix 1; alpha helix 7; the loop between alpha helix 7 & 8; alpha helix 1; alpha helix 8; the loop between beta sheet 8 & alpha helix 13; alpha helix 17; the loop between beta sheet 12 & alpha helix 18; alpha helix 2; loop between beta sheet 3 & alpha helix 3; alpha helix 3; and the loop between alpha helix 3 & 4; loop 8; beta sheet 5; loop 10; alpha helix 5; loop 11; loop 2; alpha helix 6; loop 12; alpha helix 1; alpha helix 7; loop 18; alpha helix 14; loop 26; alpha helix 2; loop 6; and alpha helix 3.


In some embodiments: the amino acid residue located in loop 8 is a residue corresponding to S123 or F124 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in beta sheet 5 is a residue corresponding to N143 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in loop 10 is a residue corresponding to T144 or T145 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in alpha helix 5 is a residue corresponding to V149 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in loop 11 is a residue corresponding to Y179 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in loop 2 is a residue corresponding to G18 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in alpha helix 6 is a residue corresponding to S180 or A181 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in loop 12 is a residue corresponding to G184, A185, V186, T187, or K189 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in alpha helix 1 is a residue corresponding to Y19 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in alpha helix 7 is a residue corresponding to H191, K192, G194, E195, or A198 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in loop 18 is a residue corresponding to F276 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in alpha helix 14 is a residue corresponding to N355 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in loop 26 is a residue corresponding to H373 or L374 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in alpha helix 2 is a residue corresponding to N47 in UGT94-289-1 (SEQ ID NO: 109); the amino acid residue located in loop 6 is a residue corresponding to H83, T84, T85, or N86 in UGT94-289-1 (SEQ ID NO: 109); and/or the amino acid residue located in alpha helix 3 is a residue corresponding to P89 or L92 in UGT94-289-1 (SEQ ID NO: 109).


In some embodiments, a UGT comprises an amino acid substitution (e.g., at least 1, 2, 3, 4, 5, 6, 7, or 8 substitutions) in a region corresponding to residues 83 to 92, 179 to 189, 1 to 82, 93 to 142, 144 to 178, 199 to 373, or 375 to 453 of UGT94-289-1 (SEQ ID NO: 109). In some embodiments, the UGT comprises an amino acid substitution at an amino acid residue corresponding to the amino acid residue in wild-type UGT94-289-1 (SEQ ID NO: 109) selected from: N143 and L374. In some embodiments, the residue corresponding to N143 is mutated to a negatively charged R group, a polar uncharged R group, or a nonpolar aliphatic R group. In some embodiments, the residue corresponding to L374 is mutated to a nonpolar aliphatic R group, a positively charged R group, a polar uncharged R group, or a nonpolar aromatic R group. In some embodiments, a UGT comprises a region that is at least 90% identical to residues 83 to 92 of UGT94-289-1 or at least 95% identical to residues 179 to 198 of UGT94-289-1. A UGT can comprise a region that is at least 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% identical, or is 100% identical, to residues 83 to 92 of UGT94-289-1. A UGT can comprise a region that is at least 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or at least 99% identical, or is 100% identical, to residues 179 to 198 of UGT94-289-1 (SEQ ID NO: 109).


In some embodiments, a host cell comprises a heterologous polynucleotide encoding a UGT, wherein the UGT comprises a region that: corresponds to residues 83 to 92 of wild-type UGT94-289-1 (SEQ ID NO: 109), wherein the region comprises an amino acid substitution relative to residues 83 to 92 of wild-type UGT94-289-1 (SEQ ID NO: 109); and/or corresponds to residues 179 to 198 of wild-type UGT94-289-1 (SEQ ID NO: 109), wherein the region comprises an amino acid substitution relative to residues 179 to 198 of wild-type UGT94-289-1 (SEQ ID NO: 109). It should be appreciated that the language “an amino acid substitution” is not limited to one amino acid substitution, but also encompasses embodiments including more than one amino acid substitution. In some embodiments, a host cell comprises a heterologous polynucleotide encoding a UGT, wherein the UGT comprises a region that: corresponds to residues 83 to 92 of wild-type UGT94-289-1 (SEQ ID NO: 109), wherein the region comprises no more than one amino acid substitution relative to residues 83 to 92 of wild-type UGT94-289-1 (SEQ ID NO: 109); and/or corresponds to residues 179 to 198 of wild-type UGT94-289-1 (SEQ ID NO: 109), wherein the region comprises no more than one amino acid substitution relative to residues 179 to 198 of wild-type UGT94-289-1 (SEQ ID NO: 109).


In some embodiments, the UGT comprises an amino acid substitution at an amino acid residue corresponding to the amino acid residue in wild-type UGT94-289-1 (SEQ ID NO: 109) selected from: H83, T84, T85, N86, P89, L92, Y179, S180, A181, G184, A185, V186, T187, K189, H191, K192, G194, E195, or A198.


In some embodiments, the residue corresponding to H83 is mutated to an amino acid comprising a polar uncharged R group or a nonpolar aromatic R group; the residue corresponding to T84 is mutated to an amino acid comprising a nonpolar aromatic R group; the residue corresponding to T85 is mutated to an amino acid comprising a nonpolar aliphatic R group, a positively charged R group, a polar uncharged R group, or a nonpolar aromatic R group; the residue corresponding to N86 is mutated to an amino acid comprising a nonpolar aliphatic R group, a polar uncharged R group, a negatively charged R group, a positively charged R group, or a nonpolar aromatic R group; the residue corresponding to P89 is mutated to an amino acid comprising a nonpolar aliphatic R group, or a polar uncharged R group; the residue corresponding to L92 is mutated to an amino acid comprising a positively charged R group; the residue corresponding to Y179 is mutated to an amino acid comprising a negatively charged R group, a nonpolar aromatic R group, a positively charged R group, or a nonpolar aliphatic R group; the residue corresponding to S180 is mutated to an amino acid comprising a nonpolar aliphatic R group; the residue corresponding to A181 is mutated to an amino acid comprising a positively charged R group or a polar uncharged R group; the residue corresponding to G184 is mutated to an amino acid comprising a nonpolar aliphatic R group, a polar uncharged R group, a negatively charged R group, a nonpolar aromatic R group, or a positively charged R group; the residue corresponding to A185 is mutated to an amino acid comprising a polar uncharged R group, a negatively charged R group, a nonpolar aliphatic R group, a positively charged R group, or a nonpolar aromatic R group; the residue corresponding to V186 is mutated to an amino acid comprising a nonpolar aliphatic R group, a polar uncharged R group, a negatively charged R group, a positively charged R group, or a nonpolar aromatic R group; the residue corresponding to T187 is mutated to an amino acid comprising a nonpolar aliphatic R group, a polar uncharged R group, a negatively charged R group, a positively charged R group, or a nonpolar aromatic R group; the residue corresponding to K189 is mutated to an amino acid comprising a nonpolar aliphatic R group, a polar uncharged R group, a negatively charged R group, a nonpolar aromatic R group, or a positively charged R group; the residue corresponding to H191 is mutated to an amino acid comprising a nonpolar aliphatic R group, a polar uncharged R group, a negatively charged R group, a positively charged R group, or a nonpolar aromatic R group; the residue corresponding to K192 is mutated to an amino acid comprising a polar uncharged R group or a nonpolar aromatic R group; the residue corresponding to G194 is mutated to an amino acid comprising a negatively charged R group, a nonpolar aliphatic R group, a polar uncharged R group, or a nonpolar aromatic R group; the residue corresponding to E195 is mutated to an amino acid comprising a nonpolar aliphatic R group, a positively charged R group, a polar uncharged R group, or a nonpolar aromatic R group; and/or the residue corresponding to A198 is mutated to an amino acid comprising a polar uncharged R group, a negatively charged R group, a nonpolar aromatic R group, a positively charged R group, or a nonpolar aliphatic R group.


In some embodiments, the UGT comprises an amino acid substitution at an amino acid residue corresponding to the amino acid residue in wild-type UGT94-289-1 (SEQ ID NO: 109) selected from: N143 and L374. In some embodiments, the residue corresponding to N143 is mutated to a negatively charged R group, a polar uncharged R group, or a nonpolar aliphatic R group. In some embodiments, the residue corresponding to L374 is mutated to a nonpolar aliphatic R group, a positively charged R group, a polar uncharged R group, or a nonpolar aromatic R group.


The UGTs of the present disclosure may be capable of glycosylating mogrol or a mogroside at any of the oxygenated sites (e.g., at C3, C11, C24, and C25). In some embodiments, the UGT is capable of branching glycosylation (e.g., branching glycosylation of a mogroside at C3 or C24).


Non-limiting examples of suitable substrates for the UGTs of the present disclosure include mogrol and mogrosides (e.g., mogroside IA1 (MIA1), mogroside IE (MIE), mogroside II-A1 (MIIA1), mogroside III-A1 (MIIIA1), mogroside II-E (MIIE), mogroside III (MIII), or mogroside III-E (MIIIE), siamenoside I).


In some embodiments, the UGTs of the present disclosure are capable of producing mogroside IA1 (MIA1), mogroside IE (MIE), mogroside II-A1 (MIIA1), mogroside II-A2 (MIIA2), mogroside III-A1 (MIIIA1), mogroside II-E (MIIE), mogroside III (MIII), siamenoside I, mogroside III-E (MIIIE), mogroside IV, mogroside IVa, isomogroside IV, and/or mogroside V.


In some embodiments, the UGT is capable of catalyzing the conversion of mogrol to MIA1; mogrol to MIE1; MIA1 to MIIA1; MIE1 to MIIE; MIIA1 to MIIIA1; MIA1 to MIIE; MIIA1 to MIII; MIIIA1 to siamenoside I; MIIE to MIII; MIII to siamenoside I; MIIE to MIIE; and/or MIIIE to siamenoside I.


It should be appreciated that activity, such as specific activity, of a UGT can be measured by any means known to one of ordinary skill in the art. In some embodiments, the activity, such as specific activity, of a UGT (e.g., a variant UGT) may be determined by measuring the amount of glycosylated mogroside produced per unit enzyme per unit time. For example, the activity, such as specific activity, may be measured in mmol glycosylated mogroside target produced per gram of enzyme per hour. A non-limiting example of a method to measure activity (e.g., specific activity) is provided in the Examples below. In some embodiments, a UGT of the present disclosure (e.g., variant UGT) may have an activity, such as specific activity, of at least 0.1 mmol (e.g., at least 1 mmol, at least 1.5 mmol, at least 2 mmol, at least 2.5 mmol, at least 3, at least 3.5 mmol, at least 4 mmol, at least 4.5 mmol, at least 5 mmol, at least 10 mmol, including all values in between) glycosylated mogroside target produced per gram of enzyme per hour.


In some embodiments, the activity, such as specific activity, of a UGT of the present disclosure is at least 1.1 fold (e.g., at least 1.3 fold, at least 1.5 fold, at least 1.7 fold, at least 1.9 fold, at least 2 fold, at least 2.5 fold, at least 3 fold, at least 4 fold, at least 5 fold, at least 10 fold, at least 20 fold, at least 30 fold, at least 40 fold, at least 50 fold, or at least 100 fold, including all values in between) greater than that of a control UGT. In some embodiments, the control UGT is UGT94-289-1 (SEQ ID NO: 109). In some embodiments, for a UGT that has an amino acid substitution, a control UGT is the same UGT but without the amino acid substitution.


It should be appreciated that one of ordinary skill in the art would be able to characterize a protein as a UGT enzyme based on structural and/or functional information associated with the protein. For example, a protein can be characterized as a UGT enzyme based on its function, such as the ability to produce one or more mogrosides in the presence of a mogroside precursor, such as mogrol.


In other embodiments, a protein can be characterized as a UGT enzyme based on the percent identity between the protein and a known UGT enzyme. For example, the protein may be at least 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical, including all values in between, to any of the UGT sequences described in this application or the sequence of any other UGT enzyme. In other embodiments, a protein can be characterized as a UGT enzyme based on the presence of one or more domains in the protein that are associated with UGT enzymes. For example, in certain embodiments, a protein is characterized as a UGT enzyme based on the presence of a sugar binding domain and/or a catalytic domain, characteristic of UGT enzymes known in the art. In certain embodiments, the catalytic domain binds the substrate to be glycosylated.


In other embodiments, a protein can be characterized as a UGT enzyme based on a comparison of the three-dimensional structure of the protein compared to the three-dimensional structure of a known UGT enzyme. For example, a protein could be characterized as a UGT based on the number or position of alpha helical domains, beta-sheet domains, etc. It should be appreciated that a UGT enzyme can be a synthetic protein.


In some embodiments, the UGT does not comprise the sequence of SEQ ID NO: 109. In some embodiments, a UGT comprises less than 95%, less than 94%, less than 93%, less than 92%, less than 91%, less than 90%, less than 89%, less than 88%, less than 87%, less than 86%, less than 85%, less than 84%, less than 83%, less than 82%, less than 81%, less than 80%, less than 79%, less than 78%, less than 77%, less than 76%, less than 75%, less than 74%, less than 73%, less than 72%, less than 71%, or less than 70% identity to SEQ ID NO: 109.


C11 Hydroxylase Enzymes


Aspects of the present disclosure provide C11 hydroxylase enzymes, which may be useful, for example, in the production of mogrol.


A C11 hydroxylase of the present disclosure may comprise a sequence that is at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 100% identical, including all values in between, with a C11 hydroxylase sequence (e.g., nucleic acid or amino acid sequence) in Table 8, with a sequence set forth as SEQ ID NOs: 113, 114, 129, or 130, or to any C11 hydroxylase sequence disclosed in this application or known in the art.


In some embodiments, a C11 hydroxylase of the present disclosure is capable of oxidizing mogrol precursors (e.g., cucurbitadienol, 11-hydroxycucurbitadienol, 24,25-dihydroxy-cucurbitadienol, and/or 24,25-epoxy-cucurbitadienol). In some embodiments, a C11 hydroxylase of the present disclosure catalyzes the formation of mogrol.


It should be appreciated that activity, such as specific activity, of a C11 hydroxylase can be determined by any means known to one of ordinary skill in the art. In some embodiments, activity (e.g., specific activity) of a C11 hydroxylase may be measured as the concentration of a mogrol precursor produced or mogrol produced per unit of enzyme per unit time. In some embodiments, a C11 hydroxylase of the present disclosure has an activity (e.g., specific activity) of at least 0.0001-0.001 μmol/min/mg, at least 0.001-0.01 μmol/min/mg, at least 0.01-0.1 μmol/min/mg, or at least 0.1-1 μmol/min/mg, including all values in between.


In some embodiments, the activity, such as specific activity, of a C11 hydroxylase is at least 1.1 fold (e.g., at least 1.3 fold, at least 1.5 fold, at least 1.7 fold, at least 1.9 fold, at least 2 fold, at least 2.5 fold, at least 3 fold, at least 4 fold, at least 5 fold, at least 10 fold, at least 20 fold, at least 30 fold, at least 40 fold, at least 50 fold, at least 100 fold, at least 1000 fold or at least 10000 fold, including all values in between) greater than that of a control C11 hydroxylase.


Cytochrome P450 Reductase Enzymes


Aspects of the present disclosure provide cytochrome P450 reductase enzymes, which may be useful, for example, in the production of mogrol. Cytochrome P450 reductase is also referred to as NADPH:ferrihemoprotein oxidoreductase, NADPH:hemoprotein oxidoreductase, NADPH:P450 oxidoreductase, P450 reductase, POR, CPR, and CYPOR. These reductases can promote C11 hydroxylase activity by catalyzing electron transfer from NADPH to a C11 hydroxylase.


Cytochrome P450 reductases of the present disclosure may comprise a sequence that is at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 100% identical, including all values in between, with a cytochrome P450 reductase sequence (e.g., nucleic acid or amino acid sequence) in Table 8, with a sequence set forth as SEQ ID NOs: 115, 116, 131, or 132, or to any cytochrome p450 reductase disclosed in this application or known in the art.


In some embodiments, a cytochrome P450 reductase of the present disclosure is capable of promoting oxidation of a mogrol precursor (e.g., cucurbitadienol, 11-hydroxy-cucurbitadienol, 24,25-dihydroxy-cucurbitadienol, and/or 24,25-epoxy-cucurbitadienol). In some embodiments, a P450 reductase of the present disclosure catalyzes the formation of a mogrol precursor or mogrol.


It should be appreciated that activity (e.g., specific activity) of a cytochrome P450 reductase can be measured by any means known to one of ordinary skill in the art. In some embodiments, activity (e.g., specific activity) of a recombinant cytochrome P450 reductase may be measured as the concentration of a mogrol precursor produced or mogrol produced per unit enzyme per unit time in the presence of a C11 hydroxylase. In some embodiments, a cytochrome P450 reductase of the present disclosure has a activity (e.g., specific activity) of at least 0.0001-0.001 μmol/min/mg, at least 0.001-0.01 μmol/min/mg, at least 0.01-0.1 μmol/min/mg, or at least 0.1-1 μmol/min/mg, including all values in between.


In some embodiments, the activity (e.g., specific activity) of a cytochrome P450 reductase is at least 1.1 fold (e.g., at least 1.3 fold, at least 1.5 fold, at least 1.7 fold, at least 1.9 fold, at least 2 fold, at least 2.5 fold, at least 3 fold, at least 4 fold, at least 5 fold, at least 10 fold, at least 20 fold, at least 30 fold, at least 40 fold, at least 50 fold, at least 100 fold, at least 1000 fold or at least 10000 fold, including all values in between) greater than that of a control cytochrome P450 reductase.


Epoxide Hydrolase Enzymes (EPHs)


Aspects of the present disclosure provide epoxide hydrolase enzymes (EPHs), which may be useful, for example, in the conversion of 24-25 epoxy-cucurbitadienol to 24-25 dihydroxy-cucurbitadienol or in the conversion of 11-hydroxy-24,25-epoxycucurbitadienol to mogrol. EPHs are capable of converting an epoxide into two hydroxyls.


EPHs of the present disclosure may comprise a sequence that is at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 100% identical, including all values in between, with a EPH sequence (e.g., nucleic acid or amino acid sequence) in Table 8, with a sequence set forth as SEQ ID NOs: 117-125 or 133-141, or to any EPH sequence disclosed in this application or known in the art.


In some embodiments, a recombinant EPH of the present disclosure is capable of promoting hydrolysis of an epoxide in a cucurbitadienol compound (e.g., hydrolysis of the epoxide in 24-25 epoxy-cucurbitadienol). In some embodiments, an EPH of the present disclosure catalyzes the formation of a mogrol precursor (e.g., 24-25 dihydroxy-cucurbitadienol).


It should be appreciated that activity (e.g., specific activity) of an EPH can be measured by any means known to one of ordinary skill in the art. In some embodiments, activity (e.g., specific activity) of an EPH may be measured as the concentration of a mogrol precursor (e.g., 24-25 dihydroxy-cucurbitadienol) or mogrol produced. In some embodiments, a recombinant EPH of the present disclosure will allow production of at least 1-100 μg/L, at least 100-1000 μg/L, at least 1-100 mg/L, at least 100-1000 mg/L, at least 1-10 g/L or at least 10-100 g/L, including all values in between.


In some embodiments, the activity (e.g., specific activity) of an EPH is at least 1.1 fold (e.g., at least 1.3 fold, at least 1.5 fold, at least 1.7 fold, at least 1.9 fold, at least 2 fold, at least 2.5 fold, at least 3 fold, at least 4 fold, at least 5 fold, at least 10 fold, at least 20 fold, at least 30 fold, at least 40 fold, at least 50 fold, or at least 100 fold, including all values in between) greater than that of a control EPH.


Squalene Epoxidases Enzymes (SQEs)


Aspects of the present disclosure provide squalene epoxidases (SQEs), which are capable of oxidizing a squalene (e.g., squalene or 2-3-oxidosqualene) to produce a squalene epoxide (e.g., 2-3-oxidosqualene or 2-3, 22-23-diepoxysqualene). SQEs may also be referred to as squalene monooxygenases.


SQEs of the present disclosure may comprise a sequence that is at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or at least 100% identical, including all values in between, with a SQE sequence (e.g., nucleic acid or amino acid sequence) in Table 8, with a sequence set forth as SEQ ID NOs: 126-128 or 142-144, or to any SQE sequence disclosed in this application or known in the art.


In some embodiments, an SQE of the present disclosure is capable of promoting formation of an epoxide in a squalene compound (e.g., epoxidation of squalene or 2,3-oxidosqualene). In some embodiments, an SQE of the present disclosure catalyzes the formation of a mogrol precursor (e.g., 2-3-oxidosqualene or 2-3, 22-23-diepoxysqualene).


Activity, such as specific activity, of a recombinant SQE may be measured as the concentration of a mogrol precursor (e.g., 2-3-oxidosqualene or 2-3, 22-23-diepoxysqualene) produced per unit of enzyme per unit of time. In some embodiments, an SQE of the present disclosure has an activity, such as specific activity, of at least 0.0000001 μmol/min/mg (e.g., at least 0.000001 μmol/min/mg, at least 0.00001 μmol/min/mg, at least 0.0001 μmol/min/mg, at least 0.001 μmol/min/mg, at least 0.01 μmol/min/mg, at least 0.1 μmol/min/mg, at least 1 μmol/min/mg, at least 10 μmol/min/mg, or at least 100 μmol/min/mg, including all values in between).


In some embodiments, the activity, such as specific activity, of a SQE is at least 1.1 fold (e.g., at least 1.3 fold, at least 1.5 fold, at least 1.7 fold, at least 1.9 fold, at least 2 fold, at least 2.5 fold, at least 3 fold, at least 4 fold, at least 5 fold, at least 10 fold, at least 20 fold, at least 30 fold, at least 40 fold, at least 50 fold, or at least 100 fold, including all values in between) greater than that of a control SQE.


Variants


Aspects of the disclosure relate to polynucleotides encoding any of the recombinant polypeptides described, such as CDS, UGT, C11 hydroxylase, cytochrome P450 reductase, and EPH, and SQE enzymes. Variants of polynucleotide or amino acid sequences described in this application are also encompassed by the present disclosure. A variant may share at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identity with a reference sequence, including all values in between.


Unless otherwise noted, the term “sequence identity,” as known in the art, refers to a relationship between the sequences of two polypeptides or polynucleotides, as determined by sequence comparison (alignment). In some embodiments, sequence identity is determined across the entire length of a sequence, while in other embodiments, sequence identity is determined over a region of a sequence.


Identity can also refer to the degree of sequence relatedness between two sequences as determined by the number of matches between strings of two or more residues (e.g., nucleic acid or amino acid residues). Identity measures the percent of identical matches between the smaller of two or more sequences with gap alignments (if any) addressed by a particular mathematical model, algorithms, or computer program.


Identity of related polypeptides or nucleic acid sequences can be readily calculated by any of the methods known to one of ordinary skill in the art. The “percent identity” of two sequences (e.g., nucleic acid or amino acid sequences) may, for example, be determined using the algorithm of Karlin and Altschul Proc. Natl. Acad. Sci. USA 87:2264-68, 1990, modified as in Karlin and Altschul Proc. Natl. Acad. Sci. USA 90:5873-77, 1993. Such an algorithm is incorporated into the NBLAST® and XBLAST® programs (version 2.0) of Altschul et al., J. Mol. Biol. 215:403-10, 1990. BLAST® protein searches can be performed, for example, with the XBLAST program, score=50, wordlength=3 to obtain amino acid sequences homologous to the protein molecules of the invention. Where gaps exist between two sequences, Gapped BLAST® can be utilized, for example, as described in Altschul et al., Nucleic Acids Res. 25(17):3389-3402, 1997. When utilizing BLAST® and Gapped BLAST® programs, the default parameters of the respective programs (e.g., XBLAST® and NBLAST®) can be used, or the parameters can be adjusted appropriately as would be understood by one of ordinary skill in the art.


Another local alignment technique which may be used, for example, is based on the Smith-Waterman algorithm (Smith, T. F. & Waterman, M. S. (1981) “Identification of common molecular subsequences.” J. Mol. Biol. 147:195-197). A general global alignment technique which may be used, for example, is the Needleman-Wunsch algorithm (Needleman, S. B. & Wunsch, C. D. (1970) “A general method applicable to the search for similarities in the amino acid sequences of two proteins.” J. Mol. Biol. 48:443-453), which is based on dynamic programming.


More recently, a Fast Optimal Global Sequence Alignment Algorithm (FOGSAA) was developed that purportedly produces global alignment of nucleic acid and amino acid sequences faster than other optimal global alignment methods, including the Needleman-Wunsch algorithm. In some embodiments, the identity of two polypeptides is determined by aligning the two amino acid sequences, calculating the number of identical amino acids, and dividing by the length of one of the amino acid sequences. In some embodiments, the identity of two nucleic acids is determined by aligning the two nucleotide sequences and calculating the number of identical nucleotide and dividing by the length of one of the nucleic acids.


For multiple sequence alignments, computer programs including Clustal Omega (Sievers et al., Mol Syst Biol. 2011 Oct. 11; 7:539) may be used.


It should be appreciated that a sequence, including a nucleic acid or amino acid sequence, may be found to have a specified percent identity to a reference sequence, such as a sequence disclosed in this application and/or recited in the claims, using any method known to one of ordinary skill in the art. Different algorithms may yield different percent identity values for a given set of sequences. The claims of this application should be understood to encompass sequences for which percent identity to a reference sequence is calculated using default parameters and/or parameters typically used by the skilled artisan for a given algorithm.


As used in this application, a residue (such as a nucleic acid residue or an amino acid residue) in sequence “X” is referred to as corresponding to a position or residue (such as a nucleic acid residue or an amino acid residue) “z” in a different sequence “Y” when the residue in sequence “X” is at the counterpart position of “z” in sequence “Y” when sequences X and Y are aligned using amino acid sequence alignment tools known in the art.


Variant sequences may be homologous sequences. As used in this application, homologous sequences are sequences (e.g., nucleic acid or amino acid sequences) that share a certain percent identity (e.g., at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 71%, at least 72%, at least 73%, at least 74%, at least 75%, at least 76%, at least 77%, at least 78%, at least 79%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% percent identity, including all values in between).


Homologous sequences include but are not limited to paralogous sequences, orthologous sequences, or sequences arising from convergent evolution. Paralogous sequences arise from duplication of a gene within a genome of a species, while orthologous sequences diverge after a speciation event. Two different species may have evolved independently but may each comprise a sequence that shares a certain percent identity with a sequence from the other species as a result of convergent evolution.


In some embodiments, a polypeptide variant (e.g., CDS, UGT, C11 hydroxylase, cytochrome P450 reductase, EPH, or SQE variant) comprises a domain that shares a secondary structure (e.g., alpha helix, beta sheet) with a reference polypeptide (e.g., a reference CDS, UGT, C11 hydroxylase, cytochrome P450 reductase, EPH, or SQE). In some embodiments, a polypeptide variant (e.g., CDS, UGT, C11 hydroxylase, cytochrome P450 reductase, EPH, or SQE variant) shares a tertiary structure with a reference polypeptide (e.g., a reference CDS, UGT, C11 hydroxylase, cytochrome P450 reductase, EPH, or SQE). As a non-limiting example, a variant polypeptide may have low primary sequence identity (e.g., less than 80%, less than 75%, less than 70%, less than 65%, less than 60%, less than 55%, less than 50%, less than 45%, less than 40%, less than 35%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, or less than 5% sequence identity) compared to a reference polypeptide, but share one or more secondary structures (e.g., including but not limited to loops, alpha helices, or beta sheets, or have the same tertiary structure as a reference polypeptide. For example, a loop may be located between a beta sheet and an alpha helix, between two alpha helices, or between two beta sheets. Homology modeling may be used to compare two or more tertiary structures.


Mutations can be made in a nucleotide sequence by a variety of methods known to one of ordinary skill in the art. For example, mutations can be made by PCR-directed mutation, site-directed mutagenesis according to the method of Kunkel (Kunkel, Proc. Nat. Acad. Sci. U.S.A. 82: 488-492, 1985), by chemical synthesis of a gene encoding a polypeptide, by gene editing tools, or by insertions, such as insertion of a tag (e.g., a HIS tag or a GFP tag). Mutations can include, for example, substitutions, deletions, and translocations, generated by any method known in the art. Methods for producing mutations may be found in in references such as Molecular Cloning: A Laboratory Manual, J. Sambrook, et al., eds., Fourth Edition, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 2012, or Current Protocols in Molecular Biology, F. M. Ausubel, et al., eds., John Wiley & Sons, Inc., New York, 2010.


In some embodiments, methods for producing variants include circular permutation (Yu and Lutz, Trends Biotechnol. 2011 January; 29(1):18-25). A non-limiting example of circular permutation is provided in Example 5 and FIG. 7. In circular permutation, the linear primary sequence of a polypeptide can be circularized (e.g., by joining the N-terminal and C-terminal ends of the sequence) and the polypeptide can be severed (“broken”) at a different location. Thus, the linear primary sequence of the new polypeptide may have low sequence identity (e.g., less than 80%, less than 75%, less than 70%, less than 65%, less than 60%, less than 55%, less than 50%, less than 45%, less than 40%, less than 35%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, less or less than 5%, including all values in between) as determined by linear sequence alignment methods (e.g., Clustal Omega or BLAST). Topological analysis of the two proteins, however, may reveal that the tertiary structure of the two polypeptides is similar or dissimilar. Without being bound by a particular theory, a variant polypeptide created through circular permutation of a reference polypeptide and with a similar tertiary structure as the reference polypeptide can share similar functional characteristics (e.g., enzymatic activity, enzyme kinetics, substrate specificity or product specificity). In some instances, circular permutation may alter the secondary structure, tertiary structure or quaternary structure and produce an enzyme with different functional characteristics (e.g., increased or decreased enzymatic activity, different substrate specificity, or different product specificity). See, e.g., Yu and Lutz, Trends Biotechnol. 2011 January; 29(1):18-25.


It should be appreciated that in a protein that has undergone circular permutation, the linear amino acid sequence of the protein would differ from a reference protein that has not undergone circular permutation. However, one of ordinary skill in the art would be able to determine which residues in the protein that has undergone circular permutation correspond to residues in the reference protein that has not undergone circular permutation by, for example, aligning the sequences and detecting conserved motifs, and/or by comparing the structures or predicted structures of the proteins, e.g., by homology modeling.


In some embodiments, an algorithm that determines the percent identity between a sequence of interest and a reference sequence described in this application accounts for the presence of circular permutation between the sequences. The presence of circular permutation may be detected using any method known in the art, including, for example, RASPODOM (Weiner et al., Bioinformatics. 2005 Apr. 1; 21(7):932-7). In some embodiments, the presence of circulation permutation is corrected for (e.g., the domains in at least one sequence are rearranged) prior to calculation of the percent identity between a sequence of interest and a sequence described in this application. The claims of this application should be understood to encompass sequences for which percent identity to a reference sequence is calculated after taking into account potential circular permutation of the sequence.


Functional variants of the recombinant CDSs, UGTs, C11 hydroxylases, cytochrome P450 reductases, EPHs, and squalene epoxidases disclosed in this application are also encompassed by the present disclosure. For example, functional variants may bind one or more of the same substrates (e.g., mogrol, mogroside, or precursors thereof) or produce one or more of the same products (e.g., mogrol, mogroside, or precursors thereof). Functional variants may be identified using any method known in the art. For example, the algorithm of Karlin and Altschul Proc. Natl. Acad. Sci. USA 87:2264-68, 1990 described above may be used to identify homologous proteins with known functions.


Putative functional variants may also be identified by searching for polypeptides with functionally annotated domains. Databases including Pfam (Sonnhammer et al., Proteins. 1997 July; 28(3):405-20) may be used to identify polypeptides with a particular domain. For example, among oxidosqualene cyclases, additional CDS enzymes may be identified in some instances by searching for polypeptides with a leucine residue corresponding to position 123 of SEQ ID NO: 74. This leucine residue has been implicated in determining the product specificity of the CDS enzyme; mutation of this residue can, for instance, result in cycloartenol or parkeol as a product (Takase et al., Org Biomol Chem. 2015 Jul. 13(26):7331-6).


Additional UGT enzymes may be identified, for example, by searching for polypeptides with a UDPGT domain (PROSITE accession number PS00375).


Homology modeling may also be used to identify amino acid residues that are amenable to mutation without affecting function. A non-limiting example of such a method may include use of position-specific scoring matrix (PSSM) and an energy minimization protocol (see, e.g., Example 5 below). See, e.g., Stormo et al., Nucleic Acids Res. 1982 May 11; 10(9):2997-3011.


PSSM may be paired with calculation of a Rosetta energy function, which determines the difference between the wild-type and the single-point mutant. Without being bound by a particular theory, potentially stabilizing mutations are desirable for protein engineering (e.g., production of functional homologs). In some embodiments, a potentially stabilizing mutation has a ΔΔGcalc value of less than −0.1 (e.g., less than −0.2, less than −0.3, less than −0.35, less than −0.4, less than −0.45, less than −0.5, less than −0.55, less than −0.6, less than −0.65, less than −0.7, less than −0.75, less than −0.8, less than −0.85, less than −0.9, less than −0.95, or less than −1.0) Rosetta energy units (R.e.u.). See, e.g., Goldenzweig et al., Mol Cell. 2016 Jul. 21; 63(2):337-346. doi: 10.1016/j.molcel.2016.06.012.


In some embodiments, a CDS, UGT, C11 hydroxylase, cytochrome P450 reductase, EPH, or SQE coding sequence comprises a mutation at 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100 or more than 100 positions corresponding to a reference coding sequence. In some embodiments, the CDS, UGT, C11 hydroxylase, cytochrome P450 reductase, EPH, or SQE coding sequence comprises a mutation in 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100 or more codons of the coding sequence relative to a reference coding sequence. As will be understood by one of ordinary skill in the art, a mutation within a codon may or may not change the amino acid that is encoded by the codon due to degeneracy of the genetic code. In some embodiments, the one or more mutations in the coding sequence do not alter the amino acid sequence of the coding sequence relative to the amino acid sequence of a reference polypeptide.


In some embodiments, the one or more mutations in a recombinant CDS, UGT, C11 hydroxylase, cytochrome P450 reductase, EPH, or SQE sequence alter the amino acid sequence of the polypeptide relative to the amino acid sequence of a reference polypeptide. In some embodiments, the one or more mutations alter the amino acid sequence of the recombinant polypeptide relative to the amino acid sequence of a reference polypeptide and alter (enhance or reduce) an activity of the polypeptide relative to the reference polypeptide.


The activity, including specific activity, of any of the recombinant polypeptides described in this application may be measured using routine methods. As a non-limiting example, a recombinant polypeptide's activity may be determined by measuring its substrate specificity, product(s) produced, the concentration of product(s) produced, or any combination thereof. As used in this application, “specific activity” of a recombinant polypeptide refers to the amount (e.g., concentration) of a particular product produced for a given amount (e.g., concentration) of the recombinant polypeptide per unit time.


The skilled artisan will also realize that mutations in a recombinant polypeptide coding sequence may result in conservative amino acid substitutions to provide functionally equivalent variants of the foregoing polypeptides, e.g., variants that retain the activities of the polypeptides. As used in this application, a “conservative amino acid substitution” refers to an amino acid substitution that does not alter the relative charge or size characteristics or functional activity of the protein in which the amino acid substitution is made.


In some instances, an amino acid is characterized by its R group (see, e.g., Table 1). For example, an amino acid may comprise a nonpolar aliphatic R group, a positively charged R group, a negatively charged R group, a nonpolar aromatic R group, or a polar uncharged R group. Non-limiting examples of an amino acid comprising a nonpolar aliphatic R group include alanine, glycine, valine, leucine, methionine, and isoleucine. Non-limiting examples of an amino acid comprising a positively charged R group includes lysine, arginine, and histidine. Non-limiting examples of an amino acid comprising a negatively charged R group include aspartate and glutamate. Non-limiting examples of an amino acid comprising a nonpolar, aromatic R group include phenylalanine, tyrosine, and tryptophan. Non-limiting examples of an amino acid comprising a polar uncharged R group include serine, threonine, cysteine, proline, asparagine, and glutamine.


Non-limiting examples of functionally equivalent variants of polypeptides may include conservative amino acid substitutions in the amino acid sequences of proteins disclosed in this application. Conservative substitutions of amino acids include substitutions made amongst amino acids within the following groups: (a) M, I, L, V; (b) F, Y, W; (c) K, R, H; (d) A, G; (e) S, T; (f) Q, N; and (g) E, D. Additional non-limiting examples of conservative amino acid substitutions are provided in Table 1.


In some embodiments, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or more than 20 residues can be changed when preparing variant polypeptides. In some embodiments, amino acids are replaced by conservative amino acid substitutions.









TABLE 1







Non-limiting Examples of conservative amino acid substitutions











Original

Conservative Amino



Residue
R Group Type
Acid Substitutions







Ala
nonpolar aliphatic R group
Cys, Gly, Ser



Arg
positively charged R group
His, Lys



Asn
polar uncharged R group
Asp, Gln, Glu



Asp
negatively charged R group
Asn, Gln, Glu



Cys
polar uncharged R group
Ala, Ser



Gln
polar uncharged R group
Asn, Asp, Glu



Glu
negatively charged R group
Asn, Asp, Gln



Gly
nonpolar aliphatic R group
Ala, Ser



His
positively charged R group
Arg, Tyr, Trp



Ile
nonpolar aliphatic R group
Leu, Met, Val



Leu
nonpolar aliphatic R group
Ile, Met, Val



Lys
positively charged R group
Arg, His



Met
nonpolar aliphatic R group
Ile, Leu, Phe, Val



Pro
polar uncharged R group



Phe
nonpolar aromatic R group
Met, Trp, Tyr



Ser
polar uncharged R group
Ala, Gly, Thr



Thr
polar uncharged R group
Ala, Asn, Ser



Trp
nonpolar aromatic R group
His, Phe, Tyr, Met



Tyr
nonpolar aromatic R group
His, Phe, Trp



Val
nonpolar aliphatic R group
Ile, Leu, Met, Thr










Amino acid substitutions in the amino acid sequence of a polypeptide to produce a recombinant polypeptide variant having a desired property and/or activity can be made by alteration of the coding sequence of the polypeptide. Similarly, conservative amino acid substitutions in the amino acid sequence of a polypeptide to produce functionally equivalent variants of the polypeptide typically are made by alteration of the coding sequence of the recombinant polypeptide (e.g., UGT, CDS, P450, cytochrome P450 reductase, EPH, or squalene epoxidase).


Expression of Nucleic Acids in Host Cells


Aspects of the present disclosure relate to the recombinant expression of genes encoding enzymes, functional modifications and variants thereof, as well as uses relating thereto. For example, the methods described in this application may be used to produce mogrol precursors, mogrol and/or mogrosides.


The term “heterologous” with respect to a polynucleotide, such as a polynucleotide comprising a gene, is used interchangeably with the term “exogenous” and the term “recombinant” and refers to: a polynucleotide that has been artificially supplied to a biological system; a polynucleotide that has been modified within a biological system; or a polynucleotide whose expression or regulation has been manipulated within a biological system. A heterologous polynucleotide that is introduced into or expressed in a host cell may be a polynucleotide that comes from a different organism or species than the host cell, or may be a synthetic polynucleotide, or may be a polynucleotide that is also endogenously expressed in the same organism or species as the host cell. For example, a polynucleotide that is endogenously expressed in a host cell may be considered heterologous when it is: situated non-naturally in the host cell; expressed recombinantly in the host cell, either stably or transiently; modified within the host cell; selectively edited within the host cell; expressed in a copy number that differs from the naturally occurring copy number within the host cell; or expressed in a non-natural way within the host cell, such as by manipulating regulatory regions that control expression of the polynucleotide. In some embodiments, a heterologous polynucleotide is a polynucleotide that is endogenously expressed in a host cell but whose expression is driven by a promoter that does not naturally regulate expression of the polynucleotide. In other embodiments, a heterologous polynucleotide is a polynucleotide that is endogenously expressed in a host cell and whose expression is driven by a promoter that does naturally regulate expression of the polynucleotide, but the promoter or another regulatory region is modified. In some embodiments, the promoter is recombinantly activated or repressed. For example, gene-editing based techniques may be used to regulate expression of a polynucleotide, including an endogenous polynucleotide, from a promoter, including an endogenous promoter. See, e.g., Chavez et al., Nat Methods. 2016 July; 13(7): 563-567. A heterologous polynucleotide may comprise a wild-type sequence or a mutant sequence as compared with a reference polynucleotide sequence.


A nucleic acid encoding any of the recombinant polypeptides, such as CDSs, UGTs, C11 hydroxylases, cytochrome P450 reductases, EPHs, or SQEs) described in this application may be incorporated into any appropriate vector through any method known in the art. For example, the vector may be an expression vector, including but not limited to a viral vector (e.g., a lentiviral, retroviral, adenoviral, or adeno-associated viral vector), any vector suitable for transient expression, any vector suitable for constitutive expression, or any vector suitable for inducible expression (e.g., a galactose-inducible or doxycycline-inducible vector). A non-limiting example of a vector for expression of a recombinant polypeptide (e.g., CDS, UGT, C11 hydroxylase, cytochrome P450 reductase, EPH, or squalene epoxidase) is described in Example 1 below.


In some embodiments, a vector replicates autonomously in the cell. A vector can contain one or more endonuclease restriction sites that are cut by a restriction endonuclease to insert and ligate a nucleic acid containing a gene described in this application to produce a recombinant vector that is able to replicate in a cell. Vectors are typically composed of DNA, although RNA vectors are also available. Cloning vectors include, but are not limited to: plasmids, fosmids, phagemids, virus genomes and artificial chromosomes. As used in this application, the terms “expression vector” or “expression construct” refer to a nucleic acid construct, generated recombinantly or synthetically, with a series of specified nucleic acid elements that permit transcription of a particular nucleic acid in a host cell, such as a yeast cell. In some embodiments, the nucleic acid sequence of a gene described in this application is inserted into a cloning vector such that it is operably joined to regulatory sequences and, in some embodiments, expressed as an RNA transcript. In some embodiments, the vector contains one or more markers, such as a selectable marker as described in this application, to identify cells transformed or transfected with the recombinant vector. In some embodiments, the nucleic acid sequence of a gene described in this application is re-coded. Re-coding may increase production of the gene product by at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or 100%, including all values in between) relative to a reference sequence that is not re-coded.


A coding sequence and a regulatory sequence are said to be “operably joined” or “operably linked” when the coding sequence and the regulatory sequence are covalently linked and the expression or transcription of the coding sequence is under the influence or control of the regulatory sequence. If the coding sequence is to be translated into a functional protein, the coding sequence and the regulatory sequence are said to be operably joined or linked if induction of a promoter in the 5′ regulatory sequence permits the coding sequence to be transcribed and if the nature of the linkage between the coding sequence and the regulatory sequence does not (1) result in the introduction of a frame-shift mutation, (2) interfere with the ability of the promoter region to direct the transcription of the coding sequence, or (3) interfere with the ability of the corresponding RNA transcript to be translated into a protein.


In some embodiments, the nucleic acid encoding any of the proteins described in this application is under the control of regulatory sequences (e.g., enhancer sequences). In some embodiments, a nucleic acid is expressed under the control of a promoter. The promoter can be a native promoter, e.g., the promoter of the gene in its endogenous context, which provides normal regulation of expression of the gene. Alternatively, a promoter can be a promoter that is different from the native promoter of the gene, e.g., the promoter is different from the promoter of the gene in its endogenous context. As used in this application, a “heterologous promoter” or “recombinant promoter” is a promoter that is not naturally or normally associated with or that does not naturally or normally control transcription of a DNA sequence to which it is operably joined. In some embodiments, a nucleotide sequence is under the control of a heterologous promoter.


In some embodiments, the promoter is a eukaryotic promoter. Non-limiting examples of eukaryotic promoters include TDH3, PGK1, PKC1, PDC1, TEF1, TEF2, RPL18B, SSA1, TDH2, PYK1, TPI1 GAL1, GAL10, GAL7, GAL3, GAL2, MET3, MET25, HXT3, HXT7, ACT1, ADH1, ADH2, CUP1-1, ENO2, and SOD1, as would be known to one of ordinary skill in the art (see, e.g., Addgene website: blog.addgene.org/plasmids-101-the-promoter-region). In some embodiments, the promoter is a prokaryotic promoter (e.g., bacteriophage or bacterial promoter). Non-limiting examples of bacteriophage promoters include Pls1con, T3, T7, SP6, and PL. Non-limiting examples of bacterial promoters include Pbad, PmgrB, Ptrc2, Plac/ara, Ptac, and Pm.


In some embodiments, the promoter is an inducible promoter. As used in this application, an “inducible promoter” is a promoter controlled by the presence or absence of a molecule. Non-limiting examples of inducible promoters include chemically-regulated promoters and physically-regulated promoters. For chemically-regulated promoters, the transcriptional activity can be regulated by one or more compounds, such as alcohol, tetracycline, galactose, a steroid, a metal, or other compounds. For physically-regulated promoters, transcriptional activity can be regulated by a phenomenon such as light or temperature. Non-limiting examples of tetracycline-regulated promoters include anhydrotetracycline (aTc)-responsive promoters and other tetracycline-responsive promoter systems (e.g., a tetracycline repressor protein (tetR), a tetracycline operator sequence (tetO) and a tetracycline transactivator fusion protein (tTA)). Non-limiting examples of steroid-regulated promoters include promoters based on the rat glucocorticoid receptor, human estrogen receptor, moth ecdysone receptors, and promoters from the steroid/retinoid/thyroid receptor superfamily. Non-limiting examples of metal-regulated promoters include promoters derived from metallothionein (proteins that bind and sequester metal ions) genes. Non-limiting examples of pathogenesis-regulated promoters include promoters induced by salicylic acid, ethylene or benzothiadiazole (BTH). Non-limiting examples of temperature/heat-inducible promoters include heat shock promoters. Non-limiting examples of light-regulated promoters include light responsive promoters from plant cells. In certain embodiments, the inducible promoter is a galactose-inducible promoter. In some embodiments, the inducible promoter is induced by one or more physiological conditions (e.g., pH, temperature, radiation, osmotic pressure, saline gradients, cell surface binding, or concentration of one or more extrinsic or intrinsic inducing agents). Non-limiting examples of an extrinsic inducer or inducing agent include amino acids and amino acid analogs, saccharides and polysaccharides, nucleic acids, protein transcriptional activators and repressors, cytokines, toxins, petroleum-based compounds, metal containing compounds, salts, ions, enzyme substrate analogs, hormones or any combination thereof.


In some embodiments, the promoter is a constitutive promoter. As used in this application, a “constitutive promoter” refers to an unregulated promoter that allows continuous transcription of a gene. Non-limiting examples of a constitutive promoter include TDH3, PGK1, PKC1, PDC1, TEF1, TEF2, RPL18B, SSA1, TDH2, PYK1, TPI1, HXT3, HXT7, ACT1, ADH1, ADH2, ENO2, and SOD1.


Other inducible promoters or constitutive promoters known to one of ordinary skill in the art are also contemplated.


The precise nature of the regulatory sequences needed for gene expression may vary between species or cell types, but generally include, as necessary, 5′ non-transcribed and 5′ non-translated sequences involved with the initiation of transcription and translation respectively, such as a TATA box, capping sequence, CAAT sequence, and the like. In particular, such 5′ non-transcribed regulatory sequences will include a promoter region which includes a promoter sequence for transcriptional control of the operably joined gene. Regulatory sequences may also include enhancer sequences or upstream activator sequences. The vectors disclosed in this application may include 5′ leader or signal sequences. The regulatory sequence may also include a terminator sequence. In some embodiments, a terminator sequence marks the end of a gene in DNA during transcription. The choice and design of one or more appropriate vectors suitable for inducing expression of one or more genes described in this application in a host cell is within the ability and discretion of one of ordinary skill in the art.


Expression vectors containing the necessary elements for expression are commercially available and known to one of ordinary skill in the art (see, e.g., Sambrook et al., Molecular Cloning: A Laboratory Manual, Fourth Edition, Cold Spring Harbor Laboratory Press, 2012).


In some embodiments, introduction of a polynucleotide, such as a polynucleotide encoding a recombinant polypeptide, into a host cell results in genomic integration of the polynucleotide. In some embodiments, a host cell comprises at least 1 copy, at least 2 copies, at least 3 copies, at least 4 copies, at least 5 copies, at least 6 copies, at least 7 copies, at least 8 copies, at least 9 copies, at least 10 copies, at least 11 copies, at least 12 copies, at least 13 copies, at least 14 copies, at least 15 copies, at least 16 copies, at least 17 copies, at least 18 copies, at least 19 copies, at least 20 copies, at least 21 copies, at least 22 copies, at least 23 copies, at least 24 copies, at least 25 copies, at least 26 copies, at least 27 copies, at least 28 copies, at least 29 copies, at least 30 copies, at least 31 copies, at least 32 copies, at least 33 copies, at least 34 copies, at least 35 copies, at least 36 copies, at least 37 copies, at least 38 copies, at least 39 copies, at least 40 copies, at least 41 copies, at least 42 copies, at least 43 copies, at least 44 copies, at least 45 copies, at least 46 copies, at least 47 copies, at least 48 copies, at least 49 copies, at least 50 copies, at least 60 copies, at least 70 copies, at least 80 copies, at least 90 copies, at least 100 copies, or more, including any values in between, of a polynucleotide sequence, such as a polynucleotide sequence encoding any of the recombinant polypeptides described in this application, in its genome.


Host Cells


Any of the proteins or enzymes of the disclosure may be expressed in a host cell. As used in this application, the term “host cell” refers to a cell that can be used to express a polynucleotide, such as a polynucleotide that encodes an enzyme used in production of mogrol, mogrosides, and precursors thereof.


Any suitable host cell may be used to produce any of the recombinant polypeptides, including CDSs, UGTs, C11 hydroxylases, cytochrome P450 reductases, EPHs, and SQEs disclosed in this application, including eukaryotic cells or prokaryotic cells. Suitable host cells include, but are not limited to, fungal cells (e.g., yeast cells), bacterial cells (e.g., E. coli cells), algal cells, plant cells, insect cells, and animal cells, including mammalian cells.


Suitable yeast host cells include, but are not limited to, Candida, Escherichia, Hansenula, Saccharomyces (e.g., S. cerevisiae), Schizosaccharomyces, Pichia, Kluyveromyces (e.g., K. lactis), and Yarrowia. In some embodiments, the yeast cell is Hansenula polymorpha, Saccharomyces cerevisiae, Saccaromyces carlsbergensis, Saccharomyces diastaticus, Saccharomyces norbensis, Saccharomyces kluyveri, Schizosaccharomyces pombe, Pichia finlandica, Pichia trehalophila, Pichia kodamae, Pichia membranaefaciens, Pichia opuntiae, Pichia thermotolerans, Pichia salictaria, Pichia quercuum, Pichia pijperi, Pichia stipitis, Pichia methanolica, Pichia angusta, Kluyveromyces lactis, Candida albicans, or Yarrowia lipolytica.


In some embodiments, the yeast strain is an industrial polyploid yeast strain. Other non-limiting examples of fungal cells include cells obtained from Aspergillus spp., Penicillium spp., Fusarium spp., Rhizopus spp., Acremonium spp., Neurospora spp., Sordaria spp., Magnaporthe spp., Allomyces spp., Ustilago spp., Botrytis spp., and Trichoderma spp.


In certain embodiments, the host cell is an algal cell such as, Chlamydomonas (e.g., C. Reinhardtii) and Phormidium (P. sp. ATCC29409).


In other embodiments, the host cell is a prokaryotic cell. Suitable prokaryotic cells include gram positive, gram negative, and gram-variable bacterial cells. The host cell may be a species of, but not limited to: Agrobacterium, Alicyclobacillus, Anabaena, Anacystis, Acinetobacter, Acidothermus, Arthrobacter, Azobacter, Bacillus, Bifidobacterium, Brevibacterium, Butyrivibrio, Buchnera, Campestris, Camplyobacter, Clostridium, Corynebacterium, Chromatium, Coprococcus, Escherichia, Enterococcus, Enterobacter, Erwinia, Fusobacterium, Faecalibacterium, Francisella, Flavobacterium, Geobacillus, Haemophilus, Helicobacter, Klebsiella, Lactobacillus, Lactococcus, Ilyobacter, Micrococcus, Microbacterium, Mesorhizobium, Methylobacterium, Methylobacterium, Mycobacterium, Neisseria, Pantoea, Pseudomonas, Prochlorococcus, Rhodobacter, Rhodopseudomonas, Rhodopseudomonas, Roseburia, Rhodospirillum, Rhodococcus, Scenedesmus, Streptomyces, Streptococcus, Synecoccus, Saccharomonospora, Saccharopolyspora, Staphylococcus, Serratia, Salmonella, Shigella, Thermoanaerobacterium, Tropheryma, Tularensis, Temecula, Thermosynechococcus, Thermococcus, Ureaplasma, Xanthomonas, Xylella, Yersinia, and Zymomonas.


In some embodiments, the bacterial host cell is of the Agrobacterium species (e.g., A. radiobacter, A. rhizogenes, A. rubi), the Arthrobacter species (e.g., A. aurescens, A. citreus, A. globformis, A. hydrocarboglutamicus, A. mysorens, A. nicotianae, A. paraffineus, A. protophonniae, A. roseoparaffinus, A. sulfureus, A. ureafaciens), or the Bacillus species (e.g., B. thuringiensis, B. anthracis, B. megaterium, B. subtilis, B. lentus, B. circulans, B. pumilus, B. lautus, B. coagulans, B. brevis, B. firmus, B. alkaophius, B. licheniformis, B. clausii, B. stearothermophilus, B. halodurans and B. amyloliquefaciens. In particular embodiments, the host cell is an industrial Bacillus strain including but not limited to B. subtilis, B. pumilus, B. licheniformis, B. megaterium, B. clausii, B. stearothermophilus and B. amyloliquefaciens. In some embodiments, the host cell is an industrial Clostridium species (e.g., C. acetobutylicum, C. tetani E88, C. lituseburense, C. saccharobutylicum, C. perfringens, C. beijerinckii). In some embodiments, the host cell is an industrial Corynebacterium species (e.g., C. glutamicum, C. acetoacidophilum). In some embodiments, the host cell is an industrial Escherichia species (e.g., E. coli). In some embodiments, the host cell is an industrial Erwinia species (e.g., E. uredovora, E. carotovora, E. ananas, E. herbicola, E. punctata, E. terreus). In some embodiments, the host cell is an industrial Pantoea species (e.g., P. citrea, P. agglomerans). In some embodiments, the host cell is an industrial Pseudomonas species, (e.g., P. putida, P. aeruginosa, P. mevalonii). In some embodiments, the host cell is an industrial Streptococcus species (e.g., S. equisimiles, S. pyogenes, S. uberis). In some embodiments, the host cell is an industrial Streptomyces species (e.g., S. ambofaciens, S. achromogenes, S. avermitilis, S. coelicolor, S. aureofaciens, S. aureus, S. fungicidicus, S. griseus, S. lividans). In some embodiments, the host cell is an industrial Zymomonas species (e.g., Z. mobilis, Z. lipolytica).


The present disclosure is also suitable for use with a variety of animal cell types, including mammalian cells, for example, human (including 293, HeLa, WI38, PER.C6 and Bowes melanoma cells), mouse (including 3T3, NS0, NS1, Sp2/0), hamster (CHO, BHK), monkey (COS, FRhL, Vero), and hybridoma cell lines.


The present disclosure is also suitable for use with a variety of plant cell types.


The term “cell,” as used in this application, may refer to a single cell or a population of cells, such as a population of cells belonging to the same cell line or strain. Use of the singular term “cell” should not be construed to refer explicitly to a single cell rather than a population of cells.


The host cell may comprise genetic modifications relative to a wild-type counterpart. As a non-limiting example, a host cell (e.g., S. cerevisiae) may be modified to reduce or inactivate one or more of the following genes: hydroxymethylglutaryl-CoA (HMG-CoA) reductase (HMG1), acetyl-CoA C-acetyltransferase (acetoacetyl-CoA thiolase) (ERG10), 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) synthase (ERG13), farnesyl-diphosphate farnesyl transferase (squalene synthase) (ERG9), may be modified to overexpress squalene epoxidase (ERG1), or may be modified to downregulate lanosterol synthase (ERG7). See, e.g., Examples 1 and 2 below.


Reduction of gene expression and/or gene inactivation may be achieved through any suitable method, including but not limited to deletion of the gene, introduction of a point mutation into the gene, truncation of the gene, introduction of an insertion into the gene, introduction of a tag or fusion into the gene, or selective editing of the gene. For example, polymerase chain reaction (PCR)-based methods may be used (see, e.g., Gardner et al., Methods Mol Biol. 2014; 1205:45-78) or well-known gene-editing techniques may be used. As a non-limiting example, genes may be deleted through gene replacement (e.g., with a marker, including a selection marker). A gene may also be truncated through the use of a transposon system (see, e.g., Poussu et al., Nucleic Acids Res. 2005; 33(12): e104).


A vector encoding any of the recombinant polypeptides described in this application may be introduced into a suitable host cell using any method known in the art. Non-limiting examples of yeast transformation protocols are described in Gietz et al., Yeast transformation can be conducted by the LiAc/SS Carrier DNA/PEG method. Methods Mol Biol. 2006; 313:107-20, which is incorporated by reference in its entirety. Host cells may be cultured under any suitable conditions as would be understood by one of ordinary skill in the art. For example, any media, temperature, and incubation conditions known in the art may be used. For host cells carrying an inducible vector, cells may be cultured with an appropriate inducible agent to promote expression.


Any of the cells disclosed in this application can be cultured in media of any type (rich or minimal) and any composition prior to, during, and/or after contact and/or integration of a nucleic acid. The conditions of the culture or culturing process can be optimized through routine experimentation as would be understood by one of ordinary skill in the art. In some embodiments, the selected media is supplemented with various components. In some embodiments, the concentration and amount of a supplemental component is optimized. In some embodiments, other aspects of the media and growth conditions (e.g., pH, temperature, etc.) are optimized through routine experimentation. In some embodiments, the frequency that the media is supplemented with one or more supplemental components, and the amount of time that the cell is cultured, is optimized.


Culturing of the cells described in this application can be performed in culture vessels known and used in the art. In some embodiments, an aerated reaction vessel (e.g., a stirred tank reactor) is used to culture the cells. In some embodiments, a bioreactor or fermentor is used to culture the cell. Thus, in some embodiments, the cells are used in fermentation. As used in this application, the terms “bioreactor” and “fermentor” are interchangeably used and refer to an enclosure, or partial enclosure, in which a biological, biochemical and/or chemical reaction takes place, involving a living organism, part of a living organism, or purified enzymes. A “large-scale bioreactor” or “industrial-scale bioreactor” is a bioreactor that is used to generate a product on a commercial or quasi-commercial scale. Large scale bioreactors typically have volumes in the range of liters, hundreds of liters, thousands of liters, or more.


Non-limiting examples of bioreactors include: stirred tank fermentors, bioreactors agitated by rotating mixing devices, chemostats, bioreactors agitated by shaking devices, airlift fermentors, packed-bed reactors, fixed-bed reactors, fluidized bed bioreactors, bioreactors employing wave induced agitation, centrifugal bioreactors, roller bottles, and hollow fiber bioreactors, roller apparatuses (for example benchtop, cart-mounted, and/or automated varieties), vertically-stacked plates, spinner flasks, stirring or rocking flasks, shaken multi-well plates, MD bottles, T-flasks, Roux bottles, multiple-surface tissue culture propagators, modified fermentors, and coated beads (e.g., beads coated with serum proteins, nitrocellulose, or carboxymethyl cellulose to prevent cell attachment).


In some embodiments, the bioreactor includes a cell culture system where the cell (e.g., yeast cell) is in contact with moving liquids and/or gas bubbles. In some embodiments, the cell or cell culture is grown in suspension. In other embodiments, the cell or cell culture is attached to a solid phase carrier. Non-limiting examples of a carrier system includes microcarriers (e.g., polymer spheres, microbeads, and microdisks that can be porous or non-porous), cross-linked beads (e.g., dextran) charged with specific chemical groups (e.g., tertiary amine groups), 2D microcarriers including cells trapped in nonporous polymer fibers, 3D carriers (e.g., carrier fibers, hollow fibers, multicartridge reactors, and semi-permeable membranes that can comprising porous fibers), microcarriers having reduced ion exchange capacity, encapsulation cells, capillaries, and aggregates. In some embodiments, carriers are fabricated from materials such as dextran, gelatin, glass, or cellulose.


In some embodiments, industrial-scale processes are operated in continuous, semi-continuous or non-continuous modes. Non-limiting examples of operation modes are batch, fed batch, extended batch, repetitive batch, draw/fill, rotating-wall, spinning flask, and/or perfusion mode of operation. In some embodiments, a bioreactor allows continuous or semi-continuous replenishment of the substrate stock, for example a carbohydrate source and/or continuous or semi-continuous separation of the product, from the bioreactor.


In some embodiments, the bioreactor or fermentor includes a sensor and/or a control system to measure and/or adjust reaction parameters. Non-limiting examples of reaction parameters include biological parameters (e.g., growth rate, cell size, cell number, cell density, cell type, or cell state, etc.), chemical parameters (e.g., pH, redox-potential, concentration of reaction substrate and/or product, concentration of dissolved gases, such as oxygen concentration and CO2 concentration, nutrient concentrations, metabolite concentrations, concentration of an oligopeptide, concentration of an amino acid, concentration of a vitamin, concentration of a hormone, concentration of an additive, serum concentration, ionic strength, concentration of an ion, relative humidity, molarity, osmolarity, concentration of other chemicals, for example buffering agents, adjuvants, or reaction by-products), physical/mechanical parameters (e.g., density, conductivity, degree of agitation, pressure, and flow rate, shear stress, shear rate, viscosity, color, turbidity, light absorption, mixing rate, conversion rate, as well as thermodynamic parameters, such as temperature, light intensity/quality, etc.). Sensors to measure the parameters described in this application are well known to one of ordinary skill in the relevant mechanical and electronic arts. Control systems to adjust the parameters in a bioreactor based on the inputs from a sensor described in this application are well known to one of ordinary skill in the art in bioreactor engineering.


In some embodiments, the method involves batch fermentation (e.g., shake flask fermentation). General considerations for batch fermentation (e.g., shake flask fermentation) include the level of oxygen and glucose. For example, batch fermentation (e.g., shake flask fermentation) may be oxygen and glucose limited, so in some embodiments, the capability of a strain to perform in a well-designed fed-batch fermentation is underestimated. Also, the final product (e.g., mogrol precursor, mogrol, mogroside precursor, or mogroside) may display some differences from the substrate (e.g., mogrol precursor, mogrol, mogroside precursor, or mogroside) in terms of solubility, toxicity, cellular accumulation and secretion and in some embodiments can have different fermentation kinetics.


The methods described in this application encompass production of the mogrol precursors (e.g., squalene, 2,3-oxidosqualene, or 24-25 epoxy-cucurbitadienol), mogrol, or mogrosides (e.g., MIA1, MIE1, MIIA1, MIIA2, MIIIA1, MIIE, MIII, siamenoside I, mogroside IV, isomogroside IV, MIIIE, and mogroside V) using a recombinant cell, cell lysate or isolated recombinant polypeptides (e.g., CDS, UGT, C11 hydroxylase, cytochrome P450 reductase, EPH, and squalene epoxidase).


Mogrol precursors (e.g., squalene, 2,3-oxidosqualene, or 24-25 epoxy-cucurbitadienol), mogrol, mogrosides (e.g., MIA1, MIE, MIIA1, MIIA2, MIIIA1, MIIE, MIII, siamenoside I, mogroside IV, isomogroside IV, MIIIE, and mogroside V) produced by any of the recombinant cells disclosed in this application may be identified and extracted using any method known in the art. Mass spectrometry (e.g., LC-MS, GC-MS) is a non-limiting example of a method for identification and may be used to help extract of a compound of interest.


The phraseology and terminology used in this application is for the purpose of description and should not be regarded as limiting. The use of terms such as “including,” “comprising,” “having,” “containing,” “involving,” and/or variations thereof in this application, is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.


The present invention is further illustrated by the following Examples, which in no way should be construed as further limiting. The entire contents of all of the references (including literature references, issued patents, published patent applications, and co pending patent applications) cited throughout this application are hereby expressly incorporated by reference.


EXAMPLES
Example 1. Identification and Functional Characterization of CDS Enzymes

A library of putative CDS enzymes was designed. The library included some oxidosqualene cyclase sequences that were modified to be more similar to CDSs.


Product made by a control strain expressing the S. grosvenorii CDS was identified as cucurbitadienol by NMR, and it was confirmed that hydroxylations of this product led to the production of mogrol. The putative CDS enzymes were evaluated to identify active enzyme(s) that catalyze cyclization of 2,3-oxidosqualene to cucurbitadienol. A total of 506 constructs from the putative CDS library were tested by transforming the library into an engineered S. cerevisiae screening strain. The S. cerevisiae screening strain comprised: a truncated HMG1 gene; overexpression of the ERG10, ERG13, ERG9, and ERG1 genes; and downregulation of the ERG7 gene. Genes encoding putative CDSs were expressed on a pESC-URA plasmid and expression was induced by culturing in SC-URA with 4% galactose. Cucurbitadienol was measured using GC-MS.


Forty CDSs were demonstrated to exhibit activity in the screen (Table 2). These CDSs included previously unidentified CDSs, as well as engineered CDSs. Some of the newly discovered enzymes showed as much as 2× or higher production of cucurbitadienol compared to the production of cucurbitadienol from a control strain that expressed a previously characterized CDS (SEQ ID NO: 73) from S. grosvenorii. SEQ ID NO: 33 is a non-limiting example of a polynucleotide sequence encoding SEQ ID NO: 73.


Therefore, various enzymes that can cyclize 2,3-oxidosqualene to cucurbitadienol have been identified and characterized.









TABLE 2







Cucurbitadienol Production by Putative CDS Enzymes.











Nucleotide
Amino Acid
cucurbitadienol


Name
Sequence
Sequence
(arbitrary units)













A0A0K9RW03_m
SEQ ID NO: 1
SEQ ID NO: 41
0.194


AquAgaCDS1_m
SEQ ID NO: 2
SEQ ID NO: 42
0.005


AquAgaCDS16
SEQ ID NO: 3
SEQ ID NO: 43
0.321


AquAgaCDS6
SEQ ID NO: 4
SEQ ID NO: 44
0.501


BenHisCDS2_m
SEQ ID NO: 5
SEQ ID NO: 45
0.016


A0A0D3QY32
SEQ ID NO: 6
SEQ ID NO: 46
0.551


A0A0D3QXV2
SEQ ID NO: 7
SEQ ID NO: 47
0.384


CmaCh17G013880.1
SEQ ID NO: 8
SEQ ID NO: 48
0.647


A0A1S3CBF6
SEQ ID NO: 9
SEQ ID NO: 49
0.749


CocGraCDS4
SEQ ID NO: 10
SEQ ID NO: 50
0.005


CocGraCDS6_m
SEQ ID NO: 11
SEQ ID NO: 51
0.032


CSPI06G07180.1
SEQ ID NO: 12
SEQ ID NO: 52
0.456


CucFoeCDS
SEQ ID NO: 13
SEQ ID NO: 53
0.366


CucMelMakCDS5
SEQ ID NO: 14
SEQ ID NO: 54
0.015


CucMetCDS
SEQ ID NO: 15
SEQ ID NO: 55
0.348


CucPepOviCDS1_m
SEQ ID NO: 16
SEQ ID NO: 56
0.007


CucPepOviCDS2
SEQ ID NO: 17
SEQ ID NO: 57
0.004


CucPepOviCDS3
SEQ ID NO: 18
SEQ ID NO: 58
0.006


CucPepOviCDS3_m
SEQ ID NO: 19
SEQ ID NO: 59
0.216


Cucsa.349060.1
SEQ ID NO: 20
SEQ ID NO: 60
0.368


F6GYI4
SEQ ID NO: 21
SEQ ID NO: 61
0.024


GynCarCDS1
SEQ ID NO: 22
SEQ ID NO: 62
0.420


GynCarCDS4
SEQ ID NO: 23
SEQ ID NO: 63
0.295


K7NBZ9
SEQ ID NO: 24
SEQ ID NO: 64
0.158


LagSicCDS2_m
SEQ ID NO: 25
SEQ ID NO: 65
0.006


Lus10014538.g_m
SEQ ID NO: 26
SEQ ID NO: 66
0.321


Lus10032146.g_m
SEQ ID NO: 27
SEQ ID NO: 67
0.163


MomChaCDS2
SEQ ID NO: 28
SEQ ID NO: 68
0.229


MomChaCDS4
SEQ ID NO: 29
SEQ ID NO: 69
0.064


O23909_PEA_Y118L
SEQ ID NO: 30
SEQ ID NO: 70
0.067


Q6BE24
SEQ ID NO: 31
SEQ ID NO: 71
0.063


SecEduCDS
SEQ ID NO: 32
SEQ ID NO: 72
0.284


SgCDS1
SEQ ID NO: 33
SEQ ID NO: 73
0.245


SgCDS_Scer1
SEQ ID NO: 34
SEQ ID NO: 74
0.857


TriKirCDS10
SEQ ID NO: 35
SEQ ID NO: 75
0.178


TriKirCDS4
SEQ ID NO: 36
SEQ ID NO: 76
0.269


XP_006340479.1
SEQ ID NO: 37
SEQ ID NO: 77
0.073


XP_008655662.1
SEQ ID NO: 38
SEQ ID NO: 78
0.021


XP_010541955.1_m
SEQ ID NO: 39
SEQ ID NO: 79
0.146


XP_016688836.1_m
SEQ ID NO: 40
SEQ ID NO: 80
0.003









It was concluded that the identified enzymes produced cucurbitadienol. GC-MS spectra of the product made by the newly discovered enzymes were very similar to cucurbitadienol produced with S. grosvenorii CDS in S. cerevisiae. This conclusion was confirmed with GC-MS, LC-MS and NMR. Cucurbitadienol made from these enzymes had a retention time, ionization pattern, and mass and fragmentation pattern identical to the cucurbitadienol made from the S. grosvenorii CDS.


Example 2. Identification and Functional Characterization of Putative UGT Enzymes

This Example describes the design and screening of a UGT library to identify UGTs capable of converting mogrol and mogroside precursors into glycosylated mogrosides. Specifically, the library aimed to identify UGTs that glycosylate at the C3 and C24 hydroxyl groups of mogrol to yield mogrosides with different glucose units. A total of 1,059 putative UGTs were obtained.


To test the UGT library, an in vitro assay was developed. Plasmids carrying UGTs were transformed into S. cerevisiae CEN.PK ΔGAL80. The UGT library was screened in this assay using a total of 8 substrates: mogrol, mogroside I-A1, mogroside I-E1, mogroside II-A1, mogroside II-E, mogroside III, mogroside III-A1, and mogroside III-E. The cell lysates were incubated with 50 μM of substrate at 30° C. for 24 hours before being quenched. Product formation was tested by LC-MS after quenching the reactions. LC-MS profiles for mogrol and mogroside standards are shown in FIG. 2.


Based on this screen, UGTs were identified that could produce known mogroside products, including mogroside I-A1 and siamenoside I (FIGS. 3A-3B). Strains identified from this screen were then tested in an additional screen (FIGS. 4A-4B, Table 3).









TABLE 3







Product Formation by Putative UGTs















Product Formation




UGT
UGT
(Peak area as


Strain
Products
Nucleotide
Amino acid
measured by LC-MS,


ID
made
sequence
sequence
in arbitrary units)





t74693
MI-A1
SEQ ID NO: 81
SEQ ID NO: 97
1.66E+08


t74692
MI-A1
SEQ ID NO: 82
SEQ ID NO: 98
5.62E+07


t85004
MI-A1
SEQ ID NO: 83
SEQ ID NO: 99
1.04E+07


t85016
MIE, MII-E,
SEQ ID NO: 84
SEQ ID NO: 100
6.14E+07,



MIII, MIII-E,


3.37E+08,



Siamenoside I


1.93E+08,






2.21E+08,






2.59E+05


t134826
MI-A1, MII-A1
SEQ ID NO: 85
SEQ ID NO: 101
1.72E+08,






8.01E+06


t72140
MI-A1, MII-E,
SEQ ID NO: 86
SEQ ID NO: 102
3.09E+07,



MIII, MIII-E,


3.79E+08,



Siamenoside I


2.14E+08,






2.28E+08,






5.69E+07


t72143
MI-A1, MII-A1,
SEQ ID NO: 87
SEQ ID NO: 103
1.21E+08,



MIII


4.24E+06,






1.18E+06


t134583
MII-E
SEQ ID NO: 88
SEQ ID NO: 104
5.48E+08


t85003
MII-E, MIII,
SEQ ID NO: 89
SEQ ID NO: 105
5.70E+07,



Siamenoside I


8.73E+07,






7.77E+05


t68041
MI-A1, MIII-A1,
SEQ ID NO: 90
SEQ ID NO: 106
8.2E+06,



MIII-E


1.83E+07,






1.02E+08


t74645
MI-A1, MII-A1,
SEQ ID NO: 91
SEQ ID NO: 107
1.55E+07



MIII-A1, MIII-E


3.07E+07,






1.9E+07,






4.24E+07


t134883
MII-E, MIII,
SEQ ID NO: 92
SEQ ID NO: 108
2.92E+08,



Siamenoside I


1.96E+08,






3.82E+07


t85024
MII-A1, MIII-E,
SEQ ID NO: 93
SEQ ID NO: 109
5.3E+07,



MIII,


2.35E+06,



Siamenoside I


4.81E+07,






3.65E+06


t134248
MI-A1, MI-E,
SEQ ID NO: 94
SEQ ID NO: 110
7.24E+06,



MII-E, MIII,


2.43E+07,



Siamenoside I


2.32E+08,






1.48E+08,






2.17E+07


t74596
Siamenoside I,
SEQ ID NO: 95
SEQ ID NO: 111
3.26E+06,



MIII-E


3.75E+07


t134224
Siamenoside I
SEQ ID NO: 96
SEQ ID NO: 112
5.83E+06









Example 3. Further Characterization of UGTs

13 of the 16 UGTs identified from the screens described in Example 2 were expressed recombinantly in E. coli and purified using a 6×His tag. Protein concentrations of these purified UGTs were determined by Bradford assay. The specific activities of the 13 UGTs were determined by incubating 50 μM of each substrate with the UGTs for 5 min at 30° C. Reactions were quenched and product concentrations quantified by LC-MS (FIG. 4). Specific activities were calculated by dividing product concentration by the enzyme concentration and reaction time. The measured specific activities ranged from 0.01 to 5.53 mmol product/(g UGT*hr), with an average of 1.14.


Example 4. Protein Engineering of UGT94-289-1

The S. cerevisiae strain t85024 (expressing a recoded polynucleotide encoding UGT94-289-1) was observed to catalyze the 6-1 & 2-1 glycosylation reactions. However, this enzyme did not catalyze these reactions at a high rate.


A library of UGT sequences was designed in which each UGT sequence contained a single amino acid substitution relative to the UGT94-289-1 sequence. The library of UGT sequences was tested for enhanced activity of the 6-1 & 2-1 glycosylations. The library contained 893 members. The positions to mutate were chosen either based on their proximity (within 4.5 angstrom) to the catalytic dyad (His21/Asp122) or based on their predicted interactions with the substrate molecules. A homology model of UGT94-289-1 is shown in FIG. 5.


The 218 mutations that improved activity over the wild-type enzyme (UGT94-289-1) were identified through an in vitro screen (Table 4). Plasmids carrying the mutated UGT94-289-1 genes were transformed into S. cerevisiae CEN.PK ΔGAL80. To test the UGT mutation library, the in vitro assay from Example 2 was performed. A total of 3 substrates-mogroside II-A1, mogroside III and mogroside II-E—were tested with the UGT mutation library using this assay.


A number of mutations were identified that enhanced the activity of these glycosylation steps (Table 4). In Table 4, MIIA1 indicates mogroside II-A1, MIIE indicates mogroside II-E, MIIIA1 indicates mogroside III-A1, MIII indicates mogroside III, MIIIE indicates mogroside III-E, and Siam indicates siamenoside I. A subset of the UGTs containing mutations identified (N143V, N143I, L374N, L374Y, and L374W) were expressed and purified in E. coli. N143V, N143I, & L374N were found to enhance the specific activities for the reactions of mogroside II-A1 to mogroside III-A1 and mogroside III to siamenoside I by 4-8× and 12-16×, respectively, above the wild-type protein. L374Y and L374W were found to enhance the specific activity for the mogroside II-E to mogroside III-E reactions by 13× and 28×, respectively, above wild-type. These observations generally match the data observed in the S. cerevisiae screen (Table 4). Additionally, the N143V mutation was observed to produce mogroside V from siamenoside which is an activity not observed in the wild-type UGT or the other mutants.


Non-limiting examples of structural motifs in UGT94-289-1 and the sequences of the structural motifs are shown in Table 5.









TABLE 4







UGT94-289-1 Substitution Mutations
















Fold



Name
Mutation
Substrate
Product
Increase
Location















UGT94-289-1
S123A
MIII
Siam
2.273
loop 8


S123A


UGT94-289-1
S123C
MIIA1
MIIIA1
2.638
loop 8


S123C


UGT94-289-1
S123G
MIII
Siam
2.242
loop 8


S123G


UGT94-289-1
S123G
MIIA1
MIIIA1
2.65
loop 8


S123G


UGT94-289-1
S123V
MIIA1
MIIIA1
8.144
loop 8


S123V


UGT94-289-1
S123V
MIIE
MIIIE
2.647
loop 8


S123V


UGT94-289-1
F124Y
MIIE
MIII
1.57
loop 8


F124Y


UGT94-289-1
N143A
MIIE
MIIIE
1.938
beta


N143A




sheet 5


UGT94-289-1
N143C
MIIE
MIIIE
6.117
beta


N143C




sheet 5


UGT94-289-1
N143C
MIII
Siam
5.461
beta


N143C




sheet 5


UGT94-289-1
N143E
MIIE
MIIIE
2.553
beta


N143E




sheet 5


UGT94-289-1
N143I
MIIE
MIIIE
21.423
beta


N143I




sheet 5


UGT94-289-1
N143I
MIII
Siam
7.092
beta


N143I




sheet 5


UGT94-289-1
N143L
MIIE
MIIIE
10.417
beta


N143L




sheet 5


UGT94-289-1
N143L
MIII
Siam
5.495
beta


N143L




sheet 5


UGT94-289-1
N143M
MIIE
MIIIE
1.82
beta


N143M




sheet 5


UGT94-289-1
N143M
MIII
Siam
3.51
beta


N143M




sheet 5


UGT94-289-1
N143Q
MIIE
MIIIE
2.27
beta


N143Q




sheet 5


UGT94-289-1
N143Q
MIII
Siam
4.59
beta


N143Q




sheet 5


UGT94-289-1
N143S
MIIE
MIIIE
4.88
beta


N143S




sheet 5


UGT94-289-1
N143S
MIII
Siam
8.245
beta


N143S




sheet 5


UGT94-289-1
N143T
MIII
Siam
4.063
beta


N143T




sheet 5


UGT94-289-1
N143V
MIIE
MIIIE
18.199
beta


N143V




sheet 5


UGT94-289-1
N143V
MIII
Siam
15.741
beta


N143V




sheet 5


UGT94-289-1
T144A
MIIE
MIIIE
1.761
loop 10


T144A


UGT94-289-1
T144C
MIIE
MIIIE
1.95
loop 10


T144C


UGT94-289-1
T144N
MIIE
MIIIE
1.767
loop 10


T144N


UGT94-289-1
T144P
MIIE
MIIIE
5.457
loop 10


T144P


UGT94-289-1
T145A
MIIE
MIIIE
5.23
loop 10


T145A


UGT94-289-1
T145A
MIII
Siam
3.754
loop 10


T145A


UGT94-289-1
T145C
MIIE
MIIIE
12.959
loop 10


T145C


UGT94-289-1
T145C
MIII
Siam
8.76
loop 10


T145C


UGT94-289-1
T145G
MIIE
MIII
2.028
loop 10


T145G


UGT94-289-1
T145G
MIIE
MIIIE
6.34
loop 10


T145G


UGT94-289-1
T145G
MIII
Siam
3.912
loop 10


T145G


UGT94-289-1
T145M
MIIE
MIIIE
2.614
loop 10


T145M


UGT94-289-1
T145N
MIIE
MIIIE
2.716
loop 10


T145N


UGT94-289-1
T145Q
MIIE
MIIIE
2.561
loop 10


T145Q


UGT94-289-1
T145S
MIIE
MIIIE
7.897
loop 10


T145S


UGT94-289-1
T145S
MIII
Siam
1.871
loop 10


T145S


UGT94-289-1
V149C
MIIE
MIII
1.694
alpha


V149C




helix 5


UGT94-289-1
V149L
MIIA1
MIIIA1
2.184
alpha


V149L




helix 5


UGT94-289-1
V149M
MIIA1
MIIIA1
3.64
alpha


V149M




helix 5


UGT94-289-1
V149M
MIIE
MIII
1.527
alpha


V149M




helix 5


UGT94-289-1
Υ179E
MIIE
MIIIE
1.938
loop 11


Y179E


UGT94-289-1
Y179F
MIIE
MIIIE
4.775
loop 11


Y179F


UGT94-289-1
Υ179H
MIIE
MIIIE
2.638
loop 11


Y179H


UGT94-289-1
Υ179I
MIIE
MIIIE
4.185
loop 11


Y179I


UGT94-289-1
Y179K
MIIE
MIIIE
1.758
loop 11


Y179K


UGT94-289-1
Y179L
MIIE
MIIIE
2.424
loop 11


Y179L


UGT94-289-1
Y179V
MIIE
MIIIE
1.789
loop 11


Y179V


UGT94-289-1
Y179W
MIIE
MIIIE
11.719
loop 11


Y179W


UGT94-289-1
G18S
MIIE
MIII
1.835
loop 2


G18S


UGT94-289-1
S180A
MIIE
MIIIE
1.749
alpha


S180A




helix 6


UGT94-289-1
S180V
MIIE
MIIIE
2.056
alpha


S180V




helix 6


UGT94-289-1
A181K
MIIE
MIII
1.813
alpha


A181K




helix 6


UGT94-289-1
A181T
MIII
Siam
2.369
alpha


A181T




helix 6


UGT94-289-1
G184A
MIIA1
MIIIA1
3.983
loop 12


G184A


UGT94-289-1
G184A
MIIE
MIII
1.716
loop 12


G184A


UGT94-289-1
G184C
MIIA1
MIIIA1
7.234
loop 12


G184C


UGT94-289-1
G184C
MIIE
MIII
1.553
loop 12


G184C


UGT94-289-1
G184D
MIIA1
MIIIA1
4.47
loop 12


G184D


UGT94-289-1
G184D
MIIE
MIII
1.584
loop 12


G184D


UGT94-289-1
G184E
MIIA1
MIIIA1
9.996
loop 12


G184E


UGT94-289-1
G184E
MIIE
MIII
1.622
loop 12


G184E


UGT94-289-1
G184F
MIIA1
MIIIA1
3.598
loop 12


G184F


UGT94-289-1
G184H
MIII
Siam
6.765
loop 12


G184H


UGT94-289-1
G184H
MIIA1
MIIIA1
6.995
loop 12


G184H


UGT94-289-1
G184I
MIIA1
MIIIA1
2.404
loop 12


G184I


UGT94-289-1
G184K
MIIA1
MIIIA1
2.887
loop 12


G184K


UGT94-289-1
G184M
MIIA1
MIIIA1
4.016
loop 12


G184M


UGT94-289-1
G184M
MIIE
MIII
1.6
loop 12


G184M


UGT94-289-1
G184N
MIII
Siam
3.221
loop 12


G184N


UGT94-289-1
G184N
MIIA1
MIIIA1
5.854
loop 12


G184N


UGT94-289-1
G184N
MIIE
MIII
1.742
loop 12


G184N


UGT94-289-1
G184P
MIIA1
MIIIA1
4.867
loop 12


G184P


UGT94-289-1
G184Q
MIIA1
MIIIA1
2.694
loop 12


G184Q


UGT94-289-1
G184Q
MIIE
MIII
1.636
loop 12


G184Q


UGT94-289-1
G184R
MIII
Siam
2.878
loop 12


G184R


UGT94-289-1
G184R
MIIA1
MIIIA1
8.334
loop 12


G184R


UGT94-289-1
G184S
MIII
Siam
2.168
loop 12


G184S


UGT94-289-1
G184S
MIIA1
MIIIA1
4.5
loop 12


G184S


UGT94-289-1
G184S
MIIE
MIII
1.679
loop 12


G184S


UGT94-289-1
G184T
MIII
Siam
3.025
loop 12


G184T


UGT94-289-1
G184T
MIIA1
MIIIA1
8.905
loop 12


G184T


UGT94-289-1
G184T
MIIE
MIII
1.637
loop 12


G184T


UGT94-289-1
G184Y
MIIA1
MIIIA1
2.622
loop 12


G184Y


UGT94-289-1
A185C
MIIA1
MIIIA1
5.499
loop 12


A185C


UGT94-289-1
A185C
MIIE
MIII
1.539
loop 12


A185C


UGT94-289-1
A185D
MIIA1
MIIIA1
6.866
loop 12


A185D


UGT94-289-1
A185D
MIIE
MIII
1.637
loop 12


A185D


UGT94-289-1
A185E
MIII
Siam
2.09
loop 12


A185E


UGT94-289-1
A185E
MIIA1
MIIIA1
12.017
loop 12


A185E


UGT94-289-1
A185G
MIII
Siam
3.325
loop 12


A185G


UGT94-289-1
A185G
MIIA1
MIIIA1
5.983
loop 12


A185G


UGT94-289-1
A185G
MIIE
MIII
1.516
loop 12


A185G


UGT94-289-1
A185K
MIIA1
MIIIA1
7.428
loop 12


A185K


UGT94-289-1
A185L
MIIA1
MIIIA1
3.769
loop 12


A185L


UGT94-289-1
A185M
MIII
Siam
8.417
loop 12


A185M


UGT94-289-1
A185M
MIIA1
MIIIA1
2.573
loop 12


A185M


UGT94-289-1
A185N
MIIA1
MIIIA1
4.856
loop 12


A185N


UGT94-289-1
A185N
MIIE
MIII
1.563
loop 12


A185N


UGT94-289-1
A185P
MIIE
MIII
1.826
loop 12


A185P


UGT94-289-1
A185Q
MIIA1
MIIIA1
4.761
loop 12


A185Q


UGT94-289-1
A185Q
MIIE
MIII
1.684
loop 12


A185Q


UGT94-289-1
A185T
MIII
Siam
2.518
loop 12


A185T


UGT94-289-1
A185W
MIIA1
MIIIA1
3.44
loop 12


A185W


UGT94-289-1
A185Y
MIII
Siam
3.144
loop 12


A185Y


UGT94-289-1
A185Y
MIIA1
MIIIA1
5.306
loop 12


A185Y


UGT94-289-1
VI86A
MIII
Siam
2.219
loop 12


VI86A


UGT94-289-1
VI86A
MIIA1
MIIIA1
4.301
loop 12


VI86A


UGT94-289-1
V186C
MIII
Siam
4.819
loop 12


V186C


UGT94-289-1
V186C
MIIA1
MIIIA1
4.066
loop 12


V186C


UGT94-289-1
V186D
MIII
Siam
4.792
loop 12


V186D


UGT94-289-1
V186D
MIIA1
MIIIA1
13.5
loop 12


V186D


UGT94-289-1
V186E
MIII
Siam
3.432
loop 12


V186E


UGT94-289-1
V186E
MIIA1
MIIIA1
11.923
loop 12


V186E


UGT94-289-1
V186G
MIII
Siam
3.306
loop 12


V186G


UGT94-289-1
V186G
MIIA1
MIIIA1
9.872
loop 12


V186G


UGT94-289-1
V186I
MIIA1
MIIIA1
4.387
loop 12


V186I


UGT94-289-1
V186K
MIIA1
MIIIA1
8.032
loop 12


V186K


UGT94-289-1
V186L
MIIA1
MIIIA1
7.942
loop 12


V186L


UGT94-289-1
V186M
MIII
Siam
2.802
loop 12


V186M


UGT94-289-1
V186M
MIIA1
MIIIA1
4.086
loop 12


V186M


UGT94-289-1
V186N
MIII
Siam
3.065
loop 12


V186N


UGT94-289-1
V186N
MIIA1
MIIIA1
4.147
loop 12


V186N


UGT94-289-1
V186P
MIIA1
MIIIA1
3.081
loop 12


V186P


UGT94-289-1
V186Q
MIIA1
MIIIA1
4.422
loop 12


V186Q


UGT94-289-1
V186R
MIIA1
MIIIA1
6.415
loop 12


V186R


UGT94-289-1
V186T
MIIA1
MIIIA1
3.906
loop 12


V186T


UGT94-289-1
V186W
MIIA1
MIIIA1
5.795
loop 12


V186W


UGT94-289-1
V186Y
MIII
Siam
4.752
loop 12


V186Y


UGT94-289-1
V186Y
MIIA1
MIIIA1
3.708
loop 12


V186Y


UGT94-289-1
T187A
MIIA1
MIIIA1
4.249
loop 12


T187A


UGT94-289-1
T187A
MIIE
MIII
1.553
loop 12


T187A


UGT94-289-1
T187C
MIIA1
MIIIA1
2.811
loop 12


T187C


UGT94-289-1
T187D
MIII
Siam
2.168
loop 12


T187D


UGT94-289-1
T187D
MIIA1
MIIIA1
6.58
loop 12


T187D


UGT94-289-1
T187D
MIIE
MIII
1.491
loop 12


T187D


UGT94-289-1
T187E
MIII
Siam
2.791
loop 12


T187E


UGT94-289-1
T187E
MIIA1
MIIIA1
8.267
loop 12


T187E


UGT94-289-1
T187G
MIIA1
MIIIA1
4.922
loop 12


T187G


UGT94-289-1
T187H
MIIA1
MIIIA1
2.132
loop 12


T187H


UGT94-289-1
T187I
MIIA1
MIIIA1
6.307
loop 12


T187I


UGT94-289-1
T187K
MIIA1
MIIIA1
7.08
loop 12


T187K


UGT94-289-1
T187L
MIIA1
MIIIA1
2.089
loop 12


T187L


UGT94-289-1
T187N
MIIA1
MIIIA1
8.746
loop 12


T187N


UGT94-289-1
T187N
MIIE
MIII
1.521
loop 12


T187N


UGT94-289-1
T187P
MIIA1
MIIIA1
2.958
loop 12


T187P


UGT94-289-1
T187R
MIII
Siam
3.005
loop 12


T187R


UGT94-289-1
T187S
MIIA1
MIIIA1
8.98
loop 12


T187S


UGT94-289-1
T187V
MIIA1
MIIIA1
4.438
loop 12


T187V


UGT94-289-1
T187V
MIIE
MIII
1.603
loop 12


T187V


UGT94-289-1
T187W
MIIA1
MIIIA1
4.221
loop 12


T187W


UGT94-289-1
T187Y
MIIA1
MIIIA1
6.997
loop 12


T187Y


UGT94-289-1
K189A
MIIA1
MIIIA1
3.76
loop 12


K189A


UGT94-289-1
K189C
MIIA1
MIIIA1
3.644
loop 12


K189C


UGT94-289-1
K189C
MIIE
MIII
1.517
loop 12


K189C


UGT94-289-1
K189D
MIIA1
MIIIA1
8.394
loop 12


K189D


UGT94-289-1
K189E
MIII
Siam
3.191
loop 12


K189E


UGT94-289-1
K189E
MIIA1
MIIIA1
13.432
loop 12


K189E


UGT94-289-1
K189F
MIIA1
MIIIA1
7.263
loop 12


K189F


UGT94-289-1
K189G
MIIA1
MIIIA1
8.815
loop 12


K189G


UGT94-289-1
K189G
MIIE
MIII
1.507
loop 12


K189G


UGT94-289-1
K189H
MIIA1
MIIIA1
4.797
loop 12


K189H


UGT94-289-1
K189I
MIII
Siam
3.884
loop 12


K189I


UGT94-289-1
K189I
MIIA1
MIIIA1
2.721
loop 12


K189I


UGT94-289-1
K189L
MIII
Siam
2.147
loop 12


K189L


UGT94-289-1
K189L
MIIA1
MIIIA1
3.223
loop 12


K189L


UGT94-289-1
K189M
MIIA1
MIIIA1
6.412
loop 12


K189M


UGT94-289-1
K189P
MIIA1
MIIIA1
7.946
loop 12


K189P


UGT94-289-1
K189P
MIIE
MIII
1.652
loop 12


K189P


UGT94-289-1
K189Q
MIIA1
MIIIA1
3.396
loop 12


K189Q


UGT94-289-1
K189R
MIIA1
MIIIA1
3.389
loop 12


K189R


UGT94-289-1
K189S
MIIA1
MIIIA1
6.478
loop 12


K189S


UGT94-289-1
K189T
MIIA1
MIIIA1
4.682
loop 12


K189T


UGT94-289-1
K189T
MIIE
MIII
1.698
loop 12


K189T


UGT94-289-1
K189V
MIII
Siam
2.113
loop 12


K189V


UGT94-289-1
K189V
MIIA1
MIIIA1
6.123
loop 12


K189V


UGT94-289-1
K189W
MIIA1
MIIIA1
2.618
loop 12


K189W


UGT94-289-1
K189Y
MIII
Siam
6.908
loop 12


K189Y


UGT94-289-1
Y19F
MIIE
MIII
1.698
alpha


Y19F




helix 1


UGT94-289-1
Y19H
MIIE
MIII
1.722
alpha


Y19H




helix 1


UGT94-289-1
Y19L
MIIE
MIII
1.729
alpha


Y19L




helix 1


UGT94-289-1
Y19V
MIIE
MIII
1.71
alpha


Y19V




helix 1


UGT94-289-1
H191A
MIIA1
MIIIA1
3.948
alpha


H191A




helix 7


UGT94-289-1
H191A
MIIE
MIII
1.516
alpha


H191A




helix 7


UGT94-289-1
H191C
MIII
Siam
3.642
alpha


H191C




helix 7


UGT94-289-1
H191C
MIIA1
MIIIA1
2.165
alpha


H191C




helix 7


UGT94-289-1
H191D
MIII
Siam
7.793
alpha


H191D




helix 7


UGT94-289-1
H191D
MIIA1
MIIIA1
4.048
alpha


H191D




helix 7


UGT94-289-1
H191E
MIII
Siam
5.036
alpha


H191E




helix 7


UGT94-289-1
H191E
MIIA1
MIIIA1
2.556
alpha


H191E




helix 7


UGT94-289-1
H191E
MIIE
MIII
1.658
alpha


H191E




helix 7


UGT94-289-1
H191G
MIII
Siam
6.242
alpha


H191G




helix 7


UGT94-289-1
H191G
MIIA1
MIIIA1
2.545
alpha


H191G




helix 7


UGT94-289-1
H191K
MIII
Siam
2.368
alpha


H191K




helix 7


UGT94-289-1
H191M
MIIA1
MIIIA1
4.329
alpha


H191M




helix 7


UGT94-289-1
H191M
MIIE
MIII
1.524
alpha


H191M




helix 7


UGT94-289-1
H191P
MIII
Siam
2.243
alpha


H191P




helix 7


UGT94-289-1
H191P
MIIA1
MIIIA1
5.514
alpha


H191P




helix 7


UGT94-289-1
H191P
MIIE
MIII
1.615
alpha


H191P




helix 7


UGT94-289-1
H191Q
MIII
Siam
6.511
alpha


H191Q




helix 7


UGT94-289-1
H191S
MIII
Siam
3.466
alpha


H191S




helix 7


UGT94-289-1
H191T
MIII
Siam
5.821
alpha


H191T




helix 7


UGT94-289-1
H191T
MIIA1
MIIIA1
2.299
alpha


H191T




helix 7


UGT94-289-1
H191V
MIII
Siam
5.918
alpha


H191V




helix 7


UGT94-289-1
H191W
MIII
Siam
3.457
alpha


H191W




helix 7


UGT94-289-1
H191Y
MIII
Siam
2.129
alpha


H191Y




helix 7


UGT94-289-1
K192C
MIIE
MIII
1.547
alpha


K192C




helix 7


UGT94-289-1
K192F
MIIE
MIII
1.579
alpha


K192F




helix 7


UGT94-289-1
G194D
MIII
Siam
2.477
alpha


G194D




helix 7


UGT94-289-1
G194L
MIIE
MIII
1.502
alpha


G194L




helix 7


UGT94-289-1
G194M
MIIA1
MIIIA1
2.722
alpha


G194M




helix 7


UGT94-289-1
G194N
MIII
Siam
2.165
alpha


G194N




helix 7


UGT94-289-1
G194P
MIII
Siam
3.154
alpha


G194P




helix 7


UGT94-289-1
G194P
MIIE
MIII
1.658
alpha


G194P




helix 7


UGT94-289-1
G194S
MIIA1
MIIIA1
2.15
alpha


G194S




helix 7


UGT94-289-1
G194W
MIIE
MIII
1.659
alpha


G194W




helix 7


UGT94-289-1
E195A
MIII
Siam
2.4
alpha


E195A




helix 7


UGT94-289-1
E195I
MIII
Siam
2.417
alpha


E195I




helix 7


UGT94-289-1
E195K
MIII
Siam
2.833
alpha


E195K




helix 7


UGT94-289-1
E195L
MIII
Siam
2.204
alpha


E195L




helix 7


UGT94-289-1
E195N
MIIA1
MIIIA1
2.471
alpha


E195N




helix 7


UGT94-289-1
E195Q
MIIA1
MIIIA1
3.857
alpha


E195Q




helix 7


UGT94-289-1
E195S
MIII
Siam
4.615
alpha


E195S




helix 7


UGT94-289-1
E195T
MIIE
MIII
1.703
alpha


E195T




helix 7


UGT94-289-1
E195Y
MIIA1
MIIIA1
4.587
alpha


E195Y




helix 7


UGT94-289-1
A198C
MIII
Siam
5.14
alpha


A198C




helix 7


UGT94-289-1
A198D
MIII
Siam
2.683
alpha


A198D




helix 7


UGT94-289-1
A198E
MIII
Siam
10.705
alpha


A198E




helix 7


UGT94-289-1
A198E
MIIA1
MIIIA1
2.252
alpha


A198E




helix 7


UGT94-289-1
A198F
MIII
Siam
5.788
alpha


A198F




helix 7


UGT94-289-1
A198H
MIII
Siam
5.034
alpha


A198H




helix 7


UGT94-289-1
A198I
MIII
Siam
33.382
alpha


A198I




helix 7


UGT94-289-1
A198I
MIIA1
MIIIA1
6.961
alpha


A198I




helix 7


UGT94-289-1
A198K
MIIA1
MIIIA1
4.659
alpha


A198K




helix 7


UGT94-289-1
A198L
MIII
Siam
5.588
alpha


A198L




helix 7


UGT94-289-1
A198L
MIIA1
MIIIA1
3.686
alpha


A198L




helix 7


UGT94-289-1
A198L
MIIE
MIII
1.921
alpha


A198L




helix 7


UGT94-289-1
A198M
MIII
Siam
11.449
alpha


A198M




helix 7


UGT94-289-1
A198M
MIIA1
MIIIA1
3.35
alpha


A198M




helix 7


UGT94-289-1
A198N
MIII
Siam
5.886
alpha


A198N




helix 7


UGT94-289-1
A198N
MIIA1
MIIIA1
3.978
alpha


A198N




helix 7


UGT94-289-1
A198P
MIII
Siam
3.242
alpha


A198P




helix 7


UGT94-289-1
A198Q
MIIA1
MIIIA1
10.477
alpha


A198Q




helix 7


UGT94-289-1
A198Q
MIIE
MIII
1.582
alpha


A198Q




helix 7


UGT94-289-1
A198R
MIII
Siam
7.871
alpha


A198R




helix 7


UGT94-289-1
A198R
MIIA1
MIIIA1
2.876
alpha


A198R




helix 7


UGT94-289-1
A198S
MIII
Siam
5.022
alpha


A198S




helix 7


UGT94-289-1
A198S
MIIA1
MIIIA1
2.141
alpha


A198S




helix 7


UGT94-289-1
A198T
MIII
Siam
9.938
alpha


A198T




helix 7


UGT94-289-1
A198V
MIII
Siam
6.579
alpha


A198V




helix 7


UGT94-289-1
A198V
MIIA1
MIIIA1
4.21
alpha


A198V




helix 7


UGT94-289-1
A198Y
MIIA1
MIIIA1
3.296
alpha


A198Y




helix 7


UGT94-289-1
A198Y
MIIE
MIII
1.585
alpha


A198Y




helix 7


UGT94-289-1
F276C
MIIE
MIII
1.889
loop 18


F276C


UGT94-289-1
F276Q
MIIE
MIII
2.273
loop 18


F276Q


UGT94-289-1
F276Q
MIIE
MIIIE
1.696
loop 18


F276Q


UGT94-289-1
N355Q
MIIE
MIIIE
2.164
alpha


N355Q




helix 14


UGT94-289-1
N355S
MIIE
MIII
2.126
alpha


N355S




helix 14


UGT94-289-1
N355S
MIIE
MIIIE
2.703
alpha


N355S




helix 14


UGT94-289-1
H373K
MIIE
MIIIE
2.226
loop 26


H373K


UGT94-289-1
H373L
MIIE
MIIIE
1.73
loop 26


H373L


UGT94-289-1
H373M
MIIE
MIIIE
2.235
loop 26


H373M


UGT94-289-1
H373R
MIIE
MIIIE
2.477
loop 26


H373R


UGT94-289-1
H373V
MIIE
MIIIE
1.978
loop 26


H373V


UGT94-289-1
H373Y
MIIE
MIIIE
1.805
loop 26


H373Y


UGT94-289-1
L374A
MIIE
MIIIE
7.024
loop 26


L374A


UGT94-289-1
L374C
MIIE
MIIIE
5.443
loop 26


L374C


UGT94-289-1
L374F
MIIE
MIIIE
3.296
loop 26


L374F


UGT94-289-1
L374H
MIIE
MIIIE
23.005
loop 26


L374H


UGT94-289-1
L374M
MIIE
MIIIE
3.215
loop 26


L374M


UGT94-289-1
L374N
MIIE
MIIIE
13.766
loop 26


L374N


UGT94-289-1
L374N
MIII
Siam
11.674
loop 26


L374N


UGT94-289-1
L374Q
MIIE
MIIIE
3.426
loop 26


L374Q


UGT94-289-1
L374Q
MIII
Siam
4.516
loop 26


L374Q


UGT94-289-1
L374S
MIII
Siam
2.463
loop 26


L374S


UGT94-289-1
L374T
MIIE
MIIIE
2.961
loop 26


L374T


UGT94-289-1
L374V
MIIE
MIIIE
3.165
loop 26


L374V


UGT94-289-1
L374W
MIIE
MIIIE
78.656
loop 26


L374W


UGT94-289-1
L374Y
MIIE
MIIIE
22.105
loop 26


L374Y


UGT94-289-1
N47G
MIIE
MIII
1.797
alpha


N47G




helix 2


UGT94-289-1
H83Q
MIIA1
MIIIA1
4.56
loop 6


H83Q


UGT94-289-1
H83Q
MIIE
MIII
1.675
loop 6


H83Q


UGT94-289-1
H83W
MIII
Siam
2.763
loop 6


H83W


UGT94-289-1
H83W
MIIA1
MIIIA1
2.302
loop 6


H83W


UGT94-289-1
T84Y
MIIE
MIIIE
2.635
loop 6


T84Y


UGT94-289-1
T85G
MIIE
MIII
1.476
loop 6


T85G


UGT94-289-1
T85K
MIIE
MIIIE
3.118
loop 6


T85K


UGT94-289-1
T85P
MIIE
MIII
1.585
loop 6


T85P


UGT94-289-1
T85S
MIIE
MIII
1.612
loop 6


T85S


UGT94-289-1
T85Y
MIIE
MIIIE
3.69
loop 6


T85Y


UGT94-289-1
N86A
MIIE
MIII
1.855
loop 6


N86A


UGT94-289-1
N86C
MIIE
MIII
1.583
loop 6


N86C


UGT94-289-1
N86E
MIIE
MIIIE
4.633
loop 6


N86E


UGT94-289-1
N86I
MIIE
MIII
1.535
loop 6


N86I


UGT94-289-1
N86K
MIIE
MIII
1.77
loop 6


N86K


UGT94-289-1
N86L
MIIE
MIII
1.59
loop 6


N86L


UGT94-289-1
N86S
MIIE
MIII
1.684
loop 6


N86S


UGT94-289-1
N86W
MIIE
MIII
1.739
loop 6


N86W


UGT94-289-1
N86Y
MIIE
MIII
1.833
loop 6


N86Y


UGT94-289-1
P89M
MIIE
MIIIE
2.041
alpha


P89M




helix 3


UGT94-289-1
P89S
MIIE
MIII
1.603
alpha


P89S




helix 3


UGT94-289-1
L92H
MIIE
MIII
1.72
alpha


L92H




helix 3


UGT94-289-1
L92K
MIIE
MIII
1.599
alpha


L92K




helix 3
















TABLE 5







Non-limiting Examples of Structural


Motifs in UGT94-289-1 (SEQ ID NO: 109)









Structural




Motif
Borders
Sequence





Loop 1
Met1-Thr9
MDAQRGHTT (SEQ ID NO: 145)





Beta Sheet 1
Thr10-Phe14
TILMF (SEQ ID NO: 146)





Loop 2
Pro15-Gly18
PWLG (SEQ ID NO: 147)





Alpha Helix 1
Tyr19-Arg34
YGHLSAFLELAKSLSR (SEQ ID NO: 148)





Loop 3
Arg35-Phe37
RNF (SEQ ID NO: 149)





Beta Sheet 2
His38-Phe41
HIYF (SEQ ID NO: 150)





Loop 4
Cys42-Thr44
CST (SEQ ID NO: 151)





Alpha Helix 2
Ser45-Ala50
SVNLDA (SEQ ID NO: 152)





Loop 5
Ile51-Ser61
IKPKLPSSSSS (SEQ ID NO: 153)





Beta Sheet 3
Asp62-Gln65
DSIQ (SEQ ID NO: 154)





Loop 6
Leu66-Leu88
LVELCLPSSPDQLPPHLHTTNAL (SEQ ID NO: 155)





Alpha Helix 3
Pro89-Ala109
PPHLMPTLHQAFSMAAQHFAA (SEQ ID NO: 156)





Loop 7
Ile110-His117
ILHTLAPH (SEQ ID NO: 157)





Beta Sheet 4
Leu118-Asp122
LLIYD (SEQ ID NO: 158)





Loop 8
Ser123-Pro126
SFQP (SEQ ID NO: 159)





Alpha Helix 4
Trp127-Leu134
WAPQLASSL (SEQ ID NO: 160)





Loop 9
Asn135-Pro137
NIP (SEQ ID NO: 161)





Beta Sheet 5
Ala138-Asn143
AINFN (SEQ ID NO: 162)





Loop 10
Thr144-Gly146
TTG (SEQ ID NO: 163)





Alpha Helix 5
Ala147-His158
ASVLTRMLHATH (SEQ ID NO: 164)





Loop 11
Tyr159-Tyr179
YPSSKFPISEFVLHDYWKAMY (SEQ ID NO: 165)





Alpha Helix 6
Ser180-Gly183
SAAG (SEQ ID NO: 166)





Loop 12
Gly184-Lys189
GAVTKK (SEQ ID NO: 167)





Alpha Helix 7
Asp190-Ser204
DHKIGETLANCLHAS (SEQ ID NO: 168)





Loop 13
Cys205-Ser206
CS (SEQ ID NO: 169)





Beta Sheet 6
Val207-Ile210
VILI (SEQ ID NO: 170)





Loop 14
Asn211-Glu217
NSFRELE (SEQ ID NO: 171)





Alpha Helix 8
Glu218-Leu227
EKYMDYLSVL (SEQ ID NO: 172)





Loop 15
Leu228-Asn229
LN (SEQ ID NO: 173)





Beta Sheet 7
Lys230-Val232
KKV (SEQ ID NO: 174)





Loop 16
Val233-Ser252
VPVGPLVYEPNQDGEDEGYS (SEQ ID NO: 175)





Alpha Helix 9
Ser253-Lys261
SIKNWLDKK (SEQ ID NO: 176)





Loop 17
Glu262-Ser265
EPSS (SEQ ID NO: 177)





Beta Sheet 8
Thr266-Ser270
TVFVS (SEQ ID NO: 178)





Loop 18
Phe271-Ser278
FGSEYFPS (SEQ ID NO: 179)





Alpha Helix 10
Lys279-Ser292
KEEMEEIAHGLEAS (SEQ ID NO: 180)





Loop 19
Glu293-His295
EVH (SEQ ID NO: 181)





Beta Sheet 9
Phe296-Val300
FIWVV (SEQ ID NO: 182)





Alpha Helix 11
Arg301-Asn307
RFPQGDN (SEQ ID NO: 183)





Loop 20
Thr308-Gly318
TSAIEDALPKG (SEQ ID NO: 184)





Alpha Helix 12
Phe319-Val323
FLERV (SEQ ID NO: 185)





Loop 21
Gly324-Gly327
GERG (SEQ ID NO: 186)





Beta Sheet 10
Met328-Lys331
MVVK (SEQ ID NO: 187)





Loop 22
Gly332-Pro335
GWAP (SEQ ID NO: 188)





Alpha Helix 13
Gln336-Lys341
QAKILK (SEQ ID NO: 189)





Loop 23
His342-Gly346
HWSTG (SEQ ID NO: 190)





Beta Sheet 11
Gly347-Ser350
GFVS (SEQ ID NO: 191)





Loop 24
His351-Gly353
HCG (SEQ ID NO: 192)





Alpha Helix 14
Trp354-Phe363
WNSVMESMMF (SEQ ID NO: 193)





Loop 25
Gly364-Pro366
GVP (SEQ ID NO: 194)





Beta Sheet 12
Ile367-Val370
IIGV (SEQ ID NO: 195)





Loop 26
Pro371-Leu374
PMHL (SEQ ID NO: 196)





Alpha Helix 15
Asp375-Ala386
DQPFNAGLAEEA (SEQ ID NO: 197)





Loop 27
Gly387-Val388
GV (SEQ ID NO: 198)





Beta Sheet 13
Gly389-Glu391
GVE (SEQ ID NO: 199)





Loop 28
Ala392-Gln401
AKRDPDGKIQ (SEQ ID NO: 200)





Alpha Helix 16
Arg402-Val414
RDEVAKLIKEVVV (SEQ ID NO: 201)





Loop 29
Glu415
E (SEQ ID NO: 202)





Alpha Helix 17
Lys416-Gly436
KTREDVRKKAREMSEILRSKG (SEQ ID NO: 203)





Loop 30
Glu437-Met440
EEKM (SEQ ID NO: 204)





Alpha Helix 18
Asp441-Leu451
DEMVAAISLFL (SEQ ID NO: 205)





Loop 31
Lys452-Ile453
KI (SEQ ID NO: 206)









Example 5. Identification and Characterization of Additional UGTs

This Example describes further engineering of a UGT enzyme and identification of additional UGT enzymes.


Engineering of a UGT involved circular permutation of the protein sequence. The predicted structure of a representative UGT, UGT94-289-1 (FIG. 5) shows that the N and C termini are flexible and in close proximity (7-10 A, FIG. 6). To circularly permute, the original N and C termini were fused together and new termini were introduced at another position within the protein structure (FIG. 7).


Two libraries were screened. One contained circularly permutated versions of a UGT sequence. The other contained additional putative UGT sequences. The S. cerevisiae strain used for the screening comprised: a CDS, two EPHs, a mutant C11-hydroxylase fusion protein, two cytochrome P450 reductases, an upregulated SQE, two primary UGTs, and two transporter knockouts. Two different biological replicates of the same strain were used for screening. The biological replicates are referred to as Background 1 and Background 2. Plasmids encoding the UGTs were transformed into the screening strain. The transformants were inoculated into preculture medium and an aliquot of the inoculated medium was subsequently transferred to production plates.


Following incubation of the production plates, mogroside production was evaluated using a thermo QQQ TSQ-Quantiva ESI with a LX4 multiplexed columns setup. The masses for select ion monitoring (SIM) for the classes of glycosylations with the mogrol backbone (M, MI, MII, MIII, MIV, MV) were as follows: 535.4 g/mol (M), 697.47 g/mol (MI), 799.51 g/mol (MII), 961.56 g/mol (MIII), 1123.61 g/mol (MIV), and 1285.68 g/mol (MV) respectively. MI indicates a product with one glucose moiety, MII indicates a product with two glucose moieties, MIII indicates a product with three glucose moieties, MIV indicates a product with four glucose moieties, and MV indicates a product with five glucose moieties. MI and MII were considered substrates of a secondary UGT, whereas MIII, MIV, and MV were considered products of a secondary UGT. These selective ion monitoring (SIM) intensities were then normalized to an internal standard and calibrated against the following surrogates: MIA1, MIIA1, MIIIA1, Siamenoside, and MV. UGT94-289-1 N143I was used as a positive control. The negative control strain did not express a secondary UGT.


The percentages of MI, MII, MIII, MIV, and MV produced by strains carrying each UGT were compared to the positive control strain. The fraction of MI, MII, MIII, MIV, and MV corresponds to the amount of each type out of the total amount of product produced.


Enzymes were designated as having UGT activity (a hit) based on the following criteria. For the circularly permutated UGT library, enzymes were considered hits if they produced a fraction of MIV (MIV fraction) greater than the mean fraction of MIV (two standard deviations of MIV fraction of each positive control strain). This cutoff was used to identify structural variants that have improved folding and stability, which could have a trade-off with activity. Only constructs that were positive in both biological replicates were considered hits. Table 6 provides data for the MIV and MV fractions.


For the library of putative UGTs, enzymes were considered hits for each product (MIII, MIV, and MV) if they were two standard deviations above the maximum observed value of the negative control strain and greater than the mean of the positive control strain. Table 7 provides data for the MIII, MIV, and MV fractions.









TABLE 6







UGTs Generated by Circular Permutation
















Back-
Back-
Back-
Back-




Amino
ground
ground
ground
ground



DNA
Acid
1
1
2
2



SEQ
SEQ
MIV
MV
MIV
MV


mID
ID NO
ID NO
fraction
fraction
fraction
fraction
















 69976


0.01
0.01
0.02
0.01


(negative


control)


2043871
317
323
0.28
0.16
0.03
0.02


2043873
209
227
0.22
0.10
0.23
0.10


2043875
219
237
0.27
0.16
0.26
0.15


2043877
222
240
0.27
0.15
0.26
0.16


2043879
329
330
0.08
0.04
0.24
0.15


2043881
216
234
0.27
0.16
0.24
0.14


2044773
207
225
0.29
0.17
0.28
0.18


2044775
210
228
0.25
0.11
0.24
0.12


2044777
220
238
0.29
0.18
0.10
0.05


2044779
318
324
0.27
0.16
0.08
0.04


2044781
213
231
0.28
0.17
0.25
0.16


2044783
217
235
0.28
0.17
0.25
0.16


2045673
319
325
0.32
0.15
0.04
0.02


2045675
211
229
0.19
0.07
0.19
0.07


2045677
221
239
0.25
0.11
0.25
0.11


2045679
223
241
0.26
0.13
0.23
0.11


2045681
214
232
0.26
0.13
0.24
0.13


2045683
218
236
0.24
0.11
0.24
0.12


2046569
208
226
0.27
0.15
0.28
0.15


2046571
212
230
0.22
0.09
0.22
0.10


2046573
320
326
0.27
0.16
0.01
0.01


2046575
224
242
0.19
0.11
0.24
0.14


2046577
215
233
0.27
0.17
0.20
0.06


2046579
321
327
0.08
0.02
0.26
0.15


1385369
322
328
0.25
0.18
0.22
0.14


(positive


control)
















TABLE 7







Additional Putative UGTs











Amino
Background 1
Background 2
















DNA
Acid
MIII
MIV
MV
MIII
MIV
MV



SEQ
SEQ
frac-
frac-
frac-
frac-
frac-
frac-


mID
ID NO
ID NO
tion
tion
tion
tion
tion
tion


















Negative


0.06
0.01
0.01
0.06
0.02
0.01


Control


Positive
322
328
0.24
0.25
0.18
0.26
0.19
0.12


Control


2502752
243
280
0.18
0.37
0.24
0.15
0.33
0.21


2502758
244
281
0.28
0.08
0.03
0.28
0.09
0.03


2502760
245
282
0.33
0.23
0.08
0.24
0.26
0.16


2502772
246
283
0.27
0.06
0.02
0.25
0.23
0.14


2502784
247
284
0.17
0.38
0.26
0.15
0.35
0.21


2502786
248
285
0.17
0.36
0.25
0.06
0.02
0.01


2502788
249
286
0.24
0.13
0.19
0.24
0.14
0.20


2502806
250
287
0.36
0.18
0.05
0.39
0.19
0.06


2502818
251
288
0.25
0.20
0.09
0.24
0.19
0.09


2502820
252
289
0.41
0.22
0.06
0.20
0.05
0.02


2502830
253
290
0.25
0.11
0.04
0.24
0.11
0.04


2502832
254
291
0.22
0.16
0.06
0.28
0.08
0.02


2502836
255
292
0.28
0.21
0.14
0.29
0.21
0.14


2502840
256
293
0.18
0.10
0.05
0.23
0.25
0.15


2502844
257
294
0.29
0.19
0.12
0.25
0.17
0.10


2502856
258
295
0.28
0.22
0.15
0.28
0.20
0.12


2502866
259
296
0.24
0.20
0.13
0.08
0.02
0.01


2502872
260
297
0.38
0.07
0.02
0.28
0.26
0.13


2502874
261
298
0.39
0.15
0.05
0.39
0.15
0.05


2502876
262
299
0.32
0.17
0.09
0.32
0.10
0.03


2502878
263
300
0.32
0.16
0.08
0.32
0.10
0.03


2502880
264
301
0.11
0.03
0.01
0.25
0.25
0.14


2502882
265
302
0.29
0.22
0.06
0.07
0.03
0.01


2502884
266
303
0.06
0.01
0.01
0.35
0.12
0.03


2502898
267
304
0.41
0.20
0.09
0.09
0.04
0.02


2502912
268
305
0.26
0.27
0.08
0.26
0.26
0.08


2502934
269
306
0.33
0.06
0.01
0.12
0.03
0.01


2502940
270
307
0.52
0.13
0.03
0.07
0.02
0.01


2502950
271
308
0.21
0.23
0.16
0.23
0.24
0.13


2502956
272
309
0.23
0.24
0.12
0.23
0.22
0.11


2502966
273
310
0.28
0.25
0.03
0.27
0.23
0.11


2502976
274
311
0.26
0.15
0.11
0.06
0.02
0.01


2503004
275
312
0.29
0.15
0.09
0.27
0.13
0.08


2503012
276
313
0.29
0.23
0.13
0.28
0.23
0.14


2503040
277
314
0.32
0.21
0.05
0.06
0.03
0.01


2503056
278
315
0.15
0.22
0.09
0.16
0.22
0.09


2503068
279
316
0.22
0.24
0.17
0.22
0.22
0.13









Example 6: Further Protein Engineering of UGTs

This Example describes further engineering of a UGT enzyme. A UGT mutation library was constructed based on a position-specific scoring matrix (PSSM) and energy minimization protocol (Goldenzweig et al., Mol Cell. 2016 Jul. 21; 63(2):337-346). In this approach, close homologs of a UGT were identified by a BLAST search. These homologs were aligned and a position-specific scoring matrix (PSSM) was calculated from the multiple sequence alignment (FIG. 8). Positions that feature greater sequence variability, such as positions 53 and 57 in FIG. 8, were positions chosen to mutate. The pool of potential amino acid changes was selected from those observed in the PSSM. For example, position 52 was mutated to either L, I, M, or V since these are amino acids observed in the PSSM at that position (FIG. 8). To reduce the mutant pool further, the impact of all potential substitutions on protein stability was evaluated using Rosetta. A pool of mutations used to construct the library comprised those substitutions observed within the PSSM that significantly enhance stability at highly variable positions (Goldenzweig et al., Mol Cell. 2016 Jul. 21; 63(2):337-346.). The library will be screened to identify enzymes with UGT activity.


Example 7: Expressing a Combination of Heterologous Enzymes to Produce a Mogrol Precursor, Mogrol, or a Mogroside

The recombinant proteins of the present disclosure are used in combination to produce a mogrol precursor, (e.g., 2-3-oxidosqualene, 2,3,22,23-dioxidosqualene, cucurbitadienol, 24,25-expoxycucurbitadienol, 24,25-dihydroxycucurbitadienol), mogrol, or mogrosides (e.g., mogroside I-A1 (MIA1), mogroside I-E (MIE), mogroside II-A1 (MIIA1), mogroside III-A1 (MIIIA1), mogroside II-E (MIIE), mogroside III (MIII), siamenoside I, mogroside IV, mogroside III-E (MIIIE), mogroside V, and mogroside VI).


For example, to produce mogrol, genes encoding enzymes such as a squalene epoxidase, a CDS, an epoxide hydrolase and a cytochrome P450 were expressed in host cells. In some instances, a cytochrome P450 reductase is also expressed in the yeast cells. Non-limiting examples of suitable squalene epoxidases, epoxide hydrolases, C11 hydroxylases and cytochrome P450 reductases are provided in Table 8 below. Non-limiting examples of CDSs are provided in Table 2. Mogrol is quantified using LC-MS. UGTs are further expressed in the host cells to produce mogrosides.


Alternatively, the recombinant proteins are purified from host cells and the mogrol is produced outside of the host cells. The recombinant proteins are added either sequentially or simultaneously to a reaction buffer comprising squalene.









TABLE 8







Non-Limiting Examples of C11 Hydroxylases (P450s),


Cytochrome P450 Reductases, Epoxide Hydrolases


(EPHs), and Squalene Epoxidases.










Nucleotide
Amino Acid


ENZYME
Sequence
Sequence





C11 hydroxylase
SEQ ID NO: 113
SEQ ID NO: 129


C11 hydroxylase
SEQ ID NO: 114
SEQ ID NO: 130


(cucurbitadienol oxidase)


Cytochrome P450
SEQ ID NO: 115
SEQ ID NO: 131


Reductase


Cytochrome P450
SEQ ID NO: 116
SEQ ID NO: 132


Reductase


Epoxide hydrolase
SEQ ID NO: 117
SEQ ID NO: 133


Epoxide hydrolase
SEQ ID NO: 118
SEQ ID NO: 134


Epoxide hydrolase (epoxide
SEQ ID NO: 119
SEQ ID NO: 135


hydratase)


Epoxide hydrolase (epoxide
SEQ ID NO: 120
SEQ ID NO: 136


hydratase)


Epoxide hydrolase (epoxide
SEQ ID NO: 121
SEQ ID NO: 137


hydratase)


Epoxide hydrolase (epoxide
SEQ ID NO: 122
SEQ ID NO: 138


hydratase)


Epoxide hydrolase (epoxide
SEQ ID NO: 123
SEQ ID NO: 139


hydratase)


Epoxide hydrolase (epoxide
SEQ ID NO: 124
SEQ ID NO: 140


hydratase)


Epoxide hydrolase (epoxide
SEQ ID NO: 125
SEQ ID NO: 141


hydratase)


Squalene epoxidase
SEQ ID NO: 126
SEQ ID NO: 142


Squalene epoxidase
SEQ ID NO: 127
SEQ ID NO: 143


Squalene epoxidase (P450)
SEQ ID NO: 128
SEQ ID NO: 144









EQUIVALENTS

Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described in this application. Such equivalents are intended to be encompassed by the following claims.


All references, including patent documents, disclosed in this application are incorporated by reference in their entirety, particularly for the disclosure referenced in this application.

Claims
  • 1. A host cell that comprises a heterologous polynucleotide encoding a cucurbitadienol synthase (CDS) enzyme, wherein the heterologous polynucleotide sequence is at least 90% identical to SEQ ID NO: 3 and/or the amino acid sequence of the CDS encoded by the heterologous polynucleotide is at least 90% identical to SEQ ID NO: 43, and wherein the host cell produces 11-hydroxycucurbitadienol, 24-25 epoxy-cucurbitadienol or cucurbitadienol, and wherein the host cell is not a plant cell.
  • 2. The host cell of claim 1, wherein the CDS comprises a leucine at the amino acid residue corresponding to the amino acid residue at position 123 of SEQ ID NO: 73.
  • 3. The host cell of claim 1, wherein the host cell further comprises one or more heterologous polynucleotides encoding a UDP-glycosyltransferase (UGT), a C11 hydroxylase, a cytochrome P450 reductase, an epoxide hydrolase (EPH), a lanosterol synthase, and/or a squalene epoxidase.
  • 4. A method of producing 11-hydroxycucurbitadienol, 24-25 epoxy-cucurbitadienol or cucurbitadienol, comprising contacting the host cell of claim 1 with 2-3-oxidosqualene or 2,3; 22,23-diepoxysqualene, thereby producing the 11-hydroxycucurbitadienol, 24-25 epoxy-cucurbitadienol or cucurbitadienol.
  • 5. The method of claim 4, wherein the method further comprises isolating the 11-hydroxycucurbitadienol, 24-25 epoxy-cucurbitadienol or cucurbitadienol.
  • 6. The host cell of claim 1, wherein the host cell is a yeast cell or a bacterial cell.
  • 7. The host cell of claim 6, wherein the host cell is a Saccharomyces cell or a Yarrowia cell.
  • 8. The host cell of claim 6, wherein the host cell is an E. coli cell.
  • 9. The host cell of claim 1, wherein the host cell produces at least 10%, 20%, or 30% more 11-hydroxycucurbitadienol, 24-25 epoxy-cucurbitadienol or cucurbitadienol relative to a control, wherein the control is a host cell that expresses S. grosvenorii CDS, encoded by a polynucleotide corresponding to SEQ ID NO: 33.
  • 10. The host cell of claim 1, wherein the CDS comprises the motif DQGWL (SEQ ID NO: 335).
  • 11. The host cell of claim 10, wherein the motif DQGWL (SEQ ID NO: 335) is located at residues in the CDS corresponding to residues 479-483 in SEQ ID NO: 73.
  • 12. The host cell of claim 1, wherein the CDS comprises the motif GHWANDLGGP (SEQ ID NO: 336).
  • 13. The host cell of claim 12, wherein the motif GHWANDLGGP (SEQ ID NO: 336) is located at residues in the CDS corresponding to residues 117-126 in SEQ ID NO: 73.
  • 14. The host cell of claim 1, wherein the CDS comprises the motif CWGVCYTYAGW (SEQ ID NO: 337).
  • 15. The host cell of claim 14, wherein the motif CWGVCYTYAGW (SEQ ID NO: 337) is located at residues in the CDS corresponding to residues 612-622 in SEQ ID NO: 73.
  • 16. The host cell of claim 1, wherein the amino acid sequence of the CDS comprises SEQ ID NO: 43.
  • 17. The host cell of claim 7, wherein the host cell is a Saccharomyces cerevisiae cell.
  • 18. The host cell of claim 7, wherein the host cell is a Yarrowia lipolytica cell.
  • 19. The host cell of claim 1, wherein the host cell is further modified to downregulate ERG7.
CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage filing under 35 U.S.C. § 371 of International Patent Application Serial No. PCT/US2019/060652, filed Nov. 9, 2019, entitled “BIOSYNTHESIS OF MOGROSIDES,” which claims the benefit of priority under 35 U.S.C. § 119(e) of U.S. Provisional Application Ser. No. 62/758,474, filed Nov. 9, 2018, entitled “Biosynthesis of Mogrosides,” the disclosure of each of which is incorporated by reference herein in its entirety.

PCT Information
Filing Document Filing Date Country Kind
PCT/US2019/060652 11/9/2019 WO
Publishing Document Publishing Date Country Kind
WO2020/097588 5/14/2020 WO A
US Referenced Citations (303)
Number Name Date Kind
5821097 Baltz et al. Oct 1998 A
5821098 Baltz et al. Oct 1998 A
5821099 Baltz et al. Oct 1998 A
5821100 Baltz et al. Oct 1998 A
5871983 Baltz et al. Feb 1999 A
5932464 Baltz et al. Aug 1999 A
6025173 Baltz et al. Feb 2000 A
6025174 Baltz et al. Feb 2000 A
6027928 Baltz et al. Feb 2000 A
6087143 Baltz et al. Jul 2000 A
6143542 Wisnewski et al. Nov 2000 A
6150415 Hammock et al. Nov 2000 A
6153397 Wisnewski et al. Nov 2000 A
6232102 Baltz et al. May 2001 B1
6498239 Baltrusch et al. Dec 2002 B1
6566100 Baltz et al. May 2003 B2
6566108 Wolf et al. May 2003 B1
6770747 Sakakibara et al. Aug 2004 B1
6809371 Sugiyama Oct 2004 B2
6828115 Zocher et al. Dec 2004 B1
6943001 Zhao et al. Sep 2005 B2
6979733 Zhao et al. Dec 2005 B2
7060477 Arand et al. Jun 2006 B2
7214786 Kovalic et al. May 2007 B2
7335504 Haupts et al. Feb 2008 B2
7351573 Dunn-Coleman et al. Apr 2008 B2
7439322 Baltz et al. Oct 2008 B2
7504490 Weinstock et al. Mar 2009 B1
7569389 Feldmann et al. Aug 2009 B2
7630836 Omura et al. Dec 2009 B2
7662583 Lim et al. Feb 2010 B2
7834146 Kovalic et al. Nov 2010 B2
7867704 Kapur et al. Jan 2011 B2
7989676 Troukhan et al. Aug 2011 B2
8003776 James et al. Aug 2011 B2
8030048 Kim et al. Oct 2011 B2
8093028 Thorson et al. Jan 2012 B2
8106174 Kovalic et al. Jan 2012 B2
8119385 Mathur et al. Feb 2012 B2
8163980 Ro et al. Apr 2012 B2
8299318 Brover et al. Oct 2012 B2
8362325 Troukhan et al. Jan 2013 B2
8399650 James et al. Mar 2013 B2
8481286 Julien et al. Jul 2013 B2
8609371 Julien et al. Dec 2013 B2
8637287 Thorson et al. Jan 2014 B2
8753842 Julien et al. Jun 2014 B2
8759632 Ro et al. Jun 2014 B2
8828684 Keasling et al. Sep 2014 B2
8962800 Mathur et al. Feb 2015 B2
9012723 Guo et al. Apr 2015 B2
9150840 Kamal et al. Oct 2015 B2
9303252 Amick et al. Apr 2016 B2
9309573 Brover et al. Apr 2016 B2
9388444 Solaiman et al. Jul 2016 B2
9562251 Kishore et al. Feb 2017 B2
9567619 Mao et al. Feb 2017 B2
9603373 Markosyan Mar 2017 B2
9611498 Wang et al. Apr 2017 B2
9631215 Houghton-Larsen et al. Apr 2017 B2
9643990 Mao et al. May 2017 B2
9701726 Troukhan et al. Jul 2017 B2
9714418 Amick et al. Jul 2017 B2
9719064 Selber et al. Aug 2017 B2
9738913 Beardslee et al. Aug 2017 B2
9745602 Daviet et al. Aug 2017 B2
9752174 Markosyan et al. Sep 2017 B2
9783566 Mao et al. Oct 2017 B2
9809829 Keasling et al. Nov 2017 B2
9822374 Katz et al. Nov 2017 B2
9834782 Poraty-Gavra et al. Dec 2017 B2
9920349 Liu et al. Mar 2018 B2
9932619 Liu et al. Apr 2018 B2
9976167 Zhou et al. May 2018 B2
10011859 Liu et al. Jul 2018 B2
10017804 Simon et al. Jul 2018 B2
10150971 Brover et al. Dec 2018 B2
10364450 Olsson et al. Jul 2019 B2
10392644 Kishore et al. Aug 2019 B2
10392673 Kino et al. Aug 2019 B2
10407706 Ono et al. Sep 2019 B2
10465222 Liu et al. Nov 2019 B2
10633685 Houghton-Larsen et al. Apr 2020 B2
10662442 Kumaran et al. May 2020 B2
10662458 Liu et al. May 2020 B2
10689682 Ono et al. Jun 2020 B2
10982249 Douchin et al. Apr 2021 B2
11060124 Patron et al. Jul 2021 B2
11091787 Houghton-Larsen et al. Aug 2021 B2
11168309 Donald et al. Nov 2021 B2
11180789 Lo et al. Nov 2021 B2
11230724 Kumaran et al. Jan 2022 B2
11248248 Houghton-Larsen Feb 2022 B2
20020155567 Baltz et al. Oct 2002 A1
20030153042 Arnold et al. Aug 2003 A1
20030215915 Wolf et al. Nov 2003 A1
20040018964 Baltz et al. Jan 2004 A1
20040031072 La Rosa et al. Feb 2004 A1
20040034888 Liu et al. Feb 2004 A1
20040123343 La Rosa et al. Jun 2004 A1
20040132055 Katz et al. Jul 2004 A1
20040172684 Kovalic et al. Sep 2004 A1
20040214272 La Rosa et al. Oct 2004 A1
20040241826 James et al. Dec 2004 A1
20050002897 Haupts et al. Jan 2005 A1
20050175581 Haupts et al. Aug 2005 A1
20060048240 Alexandrov et al. Mar 2006 A1
20060107345 Alexandrov et al. May 2006 A1
20060123505 Kikuchi et al. Jun 2006 A1
20060150283 Alexandrov et al. Jul 2006 A1
20060183202 Poppenberger et al. Aug 2006 A1
20070011783 Liu et al. Jan 2007 A1
20070042383 Kapur et al. Feb 2007 A1
20070044171 Kovalic et al. Feb 2007 A1
20070061916 Kovalic et al. Mar 2007 A1
20070107083 Poppenberger et al. May 2007 A1
20070124832 Lim et al. May 2007 A1
20070214517 Alexandrov et al. Sep 2007 A1
20070271633 Kovalic et al. Nov 2007 A9
20070277269 Alexandrov et al. Nov 2007 A1
20070283460 Liu et al. Dec 2007 A9
20080072340 Troukhan et al. Mar 2008 A1
20080145892 Donadio et al. Jun 2008 A1
20080148432 Abad Jun 2008 A1
20080293099 Ono et al. Nov 2008 A1
20090082296 James et al. Mar 2009 A1
20090087878 La Rosa et al. Apr 2009 A9
20090094717 Troukhan et al. Apr 2009 A1
20090144848 Kovalic et al. Jun 2009 A1
20090181854 Thorson et al. Jul 2009 A1
20090208440 Haupts et al. Aug 2009 A1
20090208474 Haupts et al. Aug 2009 A1
20090217406 Puzio et al. Aug 2009 A1
20100017904 Abad et al. Jan 2010 A1
20100037352 Alexandrov et al. Feb 2010 A1
20100037355 Alexandrov et al. Feb 2010 A1
20100064387 Dixon et al. Mar 2010 A1
20100083407 Feldmann et al. Apr 2010 A1
20100143915 Ronald et al. Jun 2010 A1
20100297722 Anterola et al. Nov 2010 A1
20110131679 La Rosa et al. Jun 2011 A2
20110162107 Inze et al. Jun 2011 A1
20110167514 Brover et al. Jul 2011 A1
20110179531 Kovalic et al. Jul 2011 A1
20110182862 Green et al. Jul 2011 A1
20110209246 Kovalic et al. Aug 2011 A1
20110214199 Coffin Sep 2011 A1
20110214205 Dietrich et al. Sep 2011 A1
20110214206 La Rosa et al. Sep 2011 A1
20110277178 Liu et al. Nov 2011 A1
20110277190 Abad Nov 2011 A1
20110306074 Thorson et al. Dec 2011 A1
20120011598 Troukhan et al. Jan 2012 A1
20120017292 Kovalic et al. Jan 2012 A1
20120017338 Wu et al. Jan 2012 A1
20120034689 James et al. Feb 2012 A1
20120096584 Alexandrov et al. Apr 2012 A1
20120096599 Kovalic et al. Apr 2012 A1
20120159672 Alexandrov et al. Jun 2012 A1
20120216318 La Rosa et al. Aug 2012 A1
20120246748 Guo et al. Sep 2012 A1
20130004979 Thorson et al. Jan 2013 A1
20130031668 Brover et al. Jan 2013 A1
20130097737 Kovalic et al. Apr 2013 A1
20130117886 Troukhan et al. May 2013 A1
20130131845 Guilleminot May 2013 A1
20130167263 Liu et al. Jun 2013 A1
20130171328 Kishore et al. Jul 2013 A1
20130185831 Kovalic et al. Jul 2013 A1
20130302855 Selber et al. Nov 2013 A1
20130305398 Coffin Nov 2013 A1
20130326723 La Rosa et al. Dec 2013 A1
20130333061 Wu et al. Dec 2013 A1
20130333068 Coffin Dec 2013 A1
20130337508 Fujdala et al. Dec 2013 A1
20130338348 Rommens et al. Dec 2013 A1
20140115737 Abad Apr 2014 A1
20140130203 La Rosa et al. May 2014 A1
20140165234 Dietrich et al. Jun 2014 A1
20140228586 Beardslee et al. Aug 2014 A1
20140248668 Raghavan et al. Sep 2014 A1
20140249301 Steffens Sep 2014 A1
20140259218 Kovalic et al. Sep 2014 A1
20140308698 Liu et al. Oct 2014 A1
20140325713 Kovalic et al. Oct 2014 A1
20140329281 Houghton-Larsen et al. Nov 2014 A1
20140357588 Markosyan et al. Dec 2014 A1
20140359836 Wu et al. Dec 2014 A1
20150031868 Lehmann et al. Jan 2015 A1
20150064743 Liu et al. Mar 2015 A1
20150113680 Kovalic et al. Apr 2015 A1
20150128306 Ono May 2015 A1
20150140132 Ono et al. May 2015 A1
20150143581 Liu et al. May 2015 A1
20150152146 Kovalic et al. Jun 2015 A1
20150159188 Ono et al. Jun 2015 A1
20150167015 Poraty-Gavra et al. Jun 2015 A1
20150191739 La Rosa et al. Jul 2015 A1
20150197763 La Rosa et al. Jul 2015 A1
20150197765 Guo et al. Jul 2015 A1
20150218533 Ono Aug 2015 A1
20150218588 Schalk et al. Aug 2015 A1
20150252401 Wang et al. Sep 2015 A1
20150267236 Solaiman et al. Sep 2015 A1
20150307890 Wu et al. Oct 2015 A1
20150315605 Li et al. Nov 2015 A1
20150322473 Liu Nov 2015 A1
20150361476 Simon et al. Dec 2015 A1
20150376629 Punt et al. Dec 2015 A1
20160010133 Park et al. Jan 2016 A1
20160095338 Mao et al. Apr 2016 A1
20160097063 Li et al. Apr 2016 A1
20160097070 Mao et al. Apr 2016 A1
20160097071 Mao et al. Apr 2016 A1
20160097072 Mao et al. Apr 2016 A1
20160102331 Boer et al. Apr 2016 A1
20160115515 Zhou et al. Apr 2016 A1
20160122783 Coffin May 2016 A1
20160153017 Van Der Hoeven et al. Jun 2016 A1
20160153018 Mao et al. Jun 2016 A1
20160160257 Broers et al. Jun 2016 A1
20160177360 Boer et al. Jun 2016 A1
20160185813 Galaev Jun 2016 A1
20160186225 Mikkelsen et al. Jun 2016 A1
20160198748 Prakash et al. Jul 2016 A1
20160213039 Kumar et al. Jul 2016 A1
20160215306 Baerends et al. Jul 2016 A1
20160244777 Coffin Aug 2016 A1
20160251635 Mao et al. Sep 2016 A1
20160264984 La Rosa et al. Sep 2016 A1
20160272990 Kovalic et al. Sep 2016 A1
20160298145 Laplaza et al. Oct 2016 A1
20160298159 Tao et al. Oct 2016 A1
20160319294 Kovalic et al. Nov 2016 A1
20160319295 Brover et al. Nov 2016 A1
20160319317 Ono Nov 2016 A1
20160326206 Mao et al. Nov 2016 A1
20170081691 Mao et al. Mar 2017 A1
20170114356 Li et al. Apr 2017 A1
20170119032 Patron et al. May 2017 A1
20170130233 Lang et al. May 2017 A1
20170137846 Atsumi et al. May 2017 A1
20170145396 Bott et al. May 2017 A1
20170152521 Wu et al. Jun 2017 A9
20170181452 Mao et al. Jun 2017 A1
20170196248 Mao et al. Jul 2017 A1
20170204380 Schwab Jul 2017 A1
20170211113 Tao et al. Jul 2017 A1
20170218418 Douchin et al. Aug 2017 A1
20170218419 Kishore et al. Aug 2017 A1
20170218420 Mao et al. Aug 2017 A1
20170218421 Mao et al. Aug 2017 A1
20170240942 Lunde Robertson et al. Aug 2017 A1
20170247735 Houghton-Larsen Aug 2017 A1
20170268018 Dietrich et al. Sep 2017 A1
20170275666 Prakash et al. Sep 2017 A1
20170283844 Itkin et al. Oct 2017 A1
20170298404 Mao et al. Oct 2017 A1
20170303565 Markosyan et al. Oct 2017 A1
20170306376 Raghavan et al. Oct 2017 A1
20170306377 Van Den Berg et al. Oct 2017 A1
20170314037 Kovalic et al. Nov 2017 A1
20170321238 Houghton-Larsen et al. Nov 2017 A1
20170332673 Philippe et al. Nov 2017 A1
20170356059 Kino et al. Dec 2017 A1
20170369922 Olsson et al. Dec 2017 A1
20180080055 Mao et al. Mar 2018 A1
20180142216 Naesby et al. May 2018 A1
20180230505 Boer et al. Aug 2018 A1
20180237819 Liu et al. Aug 2018 A1
20180245103 Kumaran et al. Aug 2018 A1
20180251806 Liu et al. Sep 2018 A1
20180258449 McBride et al. Sep 2018 A1
20180282776 Douchin et al. Oct 2018 A1
20180327723 Saran et al. Nov 2018 A1
20180346953 Liu et al. Dec 2018 A1
20180371517 Simon et al. Dec 2018 A1
20190071705 Parton et al. Mar 2019 A1
20190127772 Vroom et al. May 2019 A1
20190203245 Douchin et al. Jul 2019 A1
20200140838 Schoenert et al. May 2020 A1
20200165652 Houghton-Larsen May 2020 A1
20200291442 Douchin et al. Sep 2020 A1
20200325517 Houghton-Larsen et al. Oct 2020 A1
20200377865 Donald et al. Dec 2020 A1
20210032669 Philippe et al. Feb 2021 A1
20210095322 Markosyan et al. Apr 2021 A1
20210126960 Brodersen et al. Apr 2021 A1
20210207078 Love et al. Jul 2021 A1
20210324439 Patron et al. Oct 2021 A1
20210355458 Zhao et al. Nov 2021 A1
20210355517 Pauthenier et al. Nov 2021 A1
20220073960 Kishore et al. Mar 2022 A1
20220081699 Anderson et al. Mar 2022 A1
20220162658 Kumaran et al. May 2022 A1
20220170063 Itkin et al. Jun 2022 A1
20220228186 Zanghellini et al. Jul 2022 A1
20220378072 Boucher et al. Dec 2022 A1
20230042171 Goettge et al. Feb 2023 A1
20230174993 Boucher et al. Jun 2023 A1
20240158451 Becker et al. May 2024 A1
20240200114 Beaudoin et al. Jun 2024 A1
20240218403 Beaudoin et al. Jul 2024 A1
Foreign Referenced Citations (176)
Number Date Country
2019304965 Feb 2021 AU
2353910 Jun 2000 CA
2853677 May 2013 CA
2972739 Mar 2016 CA
2963300 Apr 2016 CA
2972939 Jul 2016 CA
3027180 Dec 2017 CA
3106633 Jan 2020 CA
3118467 May 2020 CA
3118675 May 2020 CA
1531590 Sep 2004 CN
104017797 Sep 2014 CN
105018438 Nov 2015 CN
104017798 Aug 2016 CN
107109377 Aug 2017 CN
107466320 Dec 2017 CN
112063678 Dec 2020 CN
113481275 Oct 2021 CN
113584110 Nov 2021 CN
113755355 Dec 2021 CN
114410492 Apr 2022 CN
0914446 May 1999 EP
0983367 Mar 2000 EP
1025213 Aug 2000 EP
1173585 Jan 2002 EP
1196590 Apr 2002 EP
1258494 Nov 2002 EP
1338608 Aug 2003 EP
1460085 Sep 2004 EP
1852508 Nov 2007 EP
1887081 Feb 2008 EP
1989302 Nov 2008 EP
2001999 Dec 2008 EP
2193140 Jun 2010 EP
2326707 Jun 2011 EP
2575432 Apr 2013 EP
2742131 Jun 2014 EP
2748303 Jul 2014 EP
2783009 Oct 2014 EP
2929043 Oct 2015 EP
3004128 Apr 2016 EP
3009508 Apr 2016 EP
3052638 Aug 2016 EP
3126492 Feb 2017 EP
3183349 Jun 2017 EP
3472308 Jun 2017 EP
3191584 Jul 2017 EP
3208342 Aug 2017 EP
3615679 Mar 2020 EP
3625334 Mar 2020 EP
3638804 Apr 2020 EP
3759230 Jan 2021 EP
3764810 Jan 2021 EP
3824093 May 2021 EP
3860364 Aug 2021 EP
3861101 Aug 2021 EP
2002-541764 Dec 2002 JP
2003-284572 Oct 2003 JP
2006-527738 Jun 2004 JP
2004-305049 Nov 2004 JP
2005-508613 Apr 2005 JP
2005-176602 Jul 2005 JP
2005-185101 Jul 2005 JP
2006-514551 May 2006 JP
2006-516885 Jul 2006 JP
2006-527590 Dec 2006 JP
2007-504836 Mar 2007 JP
2013-158297 Aug 2013 JP
2013-533736 Aug 2013 JP
2013-535206 Sep 2013 JP
2014-524246 Sep 2014 JP
2014-524247 Sep 2014 JP
2014-533518 Dec 2014 JP
2015-536157 Dec 2015 JP
2016-501040 Jan 2016 JP
2016-504023 Feb 2016 JP
2016-506739 Mar 2016 JP
2016-506743 Mar 2016 JP
2016-508378 Mar 2016 JP
2017-500056 Jan 2017 JP
2017-504341 Feb 2017 JP
2017-148050 Aug 2017 JP
2017-529860 Oct 2017 JP
6698028 May 2020 JP
1020070105563 Oct 2007 KR
20130002684 May 2013 KR
101559478 Oct 2015 KR
101791597 Oct 2017 KR
2019-0017045 Feb 2019 KR
20210066790 Jun 2021 KR
2021-0090218 Jul 2021 KR
20210089717 Jul 2021 KR
WO 9429434 Dec 1994 WO
WO 2000066716 Nov 2000 WO
WO 2002010210 Feb 2002 WO
WO 02086090 Oct 2002 WO
WO 2003072602 Sep 2003 WO
WO 2004035798 Apr 2004 WO
WO 2004113521 Dec 2004 WO
WO 2004113522 Dec 2004 WO
WO 2005080576 Sep 2005 WO
WO 2006003456 Jan 2006 WO
WO 2006014837 Feb 2006 WO
WO 2006067198 Jun 2006 WO
WO 2008034648 Mar 2008 WO
WO 2008062165 May 2008 WO
WO 2009015268 Jan 2009 WO
WO 2009093007 Jul 2009 WO
WO 2010019696 Feb 2010 WO
WO 2011153378 Dec 2011 WO
WO 2013021261 Feb 2013 WO
WO 2013076577 May 2013 WO
WO 2013137487 Sep 2013 WO
WO 2014051215 Apr 2014 WO
WO 2014067007 May 2014 WO
WO 2014081884 May 2014 WO
WO 2014086842 Jun 2014 WO
WO 2014102774 Jul 2014 WO
WO 2014191524 Dec 2014 WO
WO 2015028324 Mar 2015 WO
WO 2015048332 Apr 2015 WO
WO 2015113231 Aug 2015 WO
WO 2015197841 Dec 2015 WO
WO 2016029153 Feb 2016 WO
WO 2016038617 Mar 2016 WO
WO 2016050890 Apr 2016 WO
WO 2016060276 Apr 2016 WO
WO 2016071505 May 2016 WO
WO 2016120486 Aug 2016 WO
WO 2016151046 Sep 2016 WO
WO 2016168413 Oct 2016 WO
WO 2017000366 Jan 2017 WO
WO 2017025362 Feb 2017 WO
WO 2017025648 Feb 2017 WO
WO 2017025649 Feb 2017 WO
WO 2017031424 Feb 2017 WO
WO 2017053574 Mar 2017 WO
WO 2017066845 Apr 2017 WO
WO 2017075257 May 2017 WO
WO 2017085028 May 2017 WO
WO 2017098017 Jun 2017 WO
WO 2017153538 Sep 2017 WO
WO 2017178632 Oct 2017 WO
WO 2017198681 Nov 2017 WO
WO 2017198682 Nov 2017 WO
WO 2017207484 Dec 2017 WO
WO 2017218324 Dec 2017 WO
WO 2018144996 Aug 2018 WO
WO 2018083338 Nov 2018 WO
WO 2018204483 Nov 2018 WO
WO 2018211032 Nov 2018 WO
WO 2018229283 Dec 2018 WO
WO 2019113387 Jun 2019 WO
WO 2019169027 Sep 2019 WO
WO 2019211230 Nov 2019 WO
WO 2020018506 Jan 2020 WO
WO 2020051488 Mar 2020 WO
WO 2020081739 Apr 2020 WO
WO 2020096905 May 2020 WO
WO 2020096907 May 2020 WO
WO 2020097588 May 2020 WO
WO 2020237226 Nov 2020 WO
WO 2020264179 Dec 2020 WO
WO 2021202513 Jan 2021 WO
WO 2021081327 Apr 2021 WO
WO 2021126960 Jun 2021 WO
WO 2021174092 Sep 2021 WO
WO 2021188456 Sep 2021 WO
WO 2021188457 Sep 2021 WO
WO 2021188703 Sep 2021 WO
WO 2021231728 Nov 2021 WO
WO 2022115527 Jun 2022 WO
WO 2022133314 Jun 2022 WO
WO 2022192688 Sep 2022 WO
WO 2022212917 Oct 2022 WO
WO 2022212924 Oct 2022 WO
Non-Patent Literature Citations (116)
Entry
Qiao, J., Luo, Z., Gu, Z., Zhang, Y., Zhang, X., & Ma, X. (2019). Identification of a novel specific cucurbitadienol synthase allele in Siraitia grosvenorii correlates with high catalytic efficiency. Molecules, 24(3), 627. (Year: 2019).
Cleveland Clinic. (May 12, 2021). Enzymes. Cleveland Clinic; Cleveland Clinic. https://my.clevelandclinic.org/health/articles/21532-enzymes (Year: 2021).
Wang, J., Guo, Y., Yin, X., Wang, X., Qi, X., & Xue, Z. (2022). Diverse triterpene skeletons are derived from the expansion and divergent evolution of 2, 3-oxidosqualene cyclases in plants. Critical Reviews in Biochemistry and Molecular Biology, 57(2), 113-132. (Year: 2022).
National Center for Biotechnology Information (2024). PubChem Compound Summary for CID 5366020, 2,3-Oxidosqualene. Retrieved May 8, 2024 from https://pubchem.ncbi.nlm.nih.gov/compound/2_3-Oxidosqualene. (Year: 2024).
Translation of Ma CN104017797 retrieved from Espacenet on Oct. 1, 2024 from https://worldwide.espacenet.com/patent/search/family/051434798/publication/CN104017797A?q=CN104017797 (Year: 2024).
Invitation to Pay Additional Fees for Application No. PCT/US2019/060652, mailed Dec. 18, 2019.
International Search Report and Written Opinion for Application No. PCT/US2019/060652, mailed Feb. 3, 2020.
International Preliminary Report on Patentability (Chapter II) for Application No. PCT/US2019/060652, mailed Feb. 18, 2021.
You et al., Molecular Cloning and Sequencing of an Allium macrostemon cDNA Probably Encoding Oxidosqualene Cyclase. Plant Biotechnol. 1999;16(4):311-314.
Abghari et al., Combinatorial Engineering of Yarrowia lipolytica as a Promising Cell Biorefinery Platform for the de novo Production of Multi-Purpose Long Chain Dicarboxylic Acids. Fermentation. Aug. 18, 2017;3(40):1-30. doi: :10.3390/fermentation3030040.
Gruchattka et al., In silico profiling of Escherichia coli and Saccharomyces cerevisiae as terpenoid factories. Microb Cell Fact. Sep. 23, 2013;12:84. doi: 10.1186/1475-2859-12-84.
Mishra et al., Genome-scale model-driven strain design for dicarboxylic acid production in Yarrowia lipolytica. BMC Syst Biol. Mar. 19, 2018;12(Suppl 2):12. doi: 10.1186/s12918-018-0542-5.
Paramasivan et al., Progress in terpene synthesis strategies through engineering of Saccharomyces cerevisiae. Crit Rev Biotechnol. Dec. 2017;37(8):974-989. doi: 10.1080/07388551.2017.1299679. Epub Apr. 20, 2017.
Sun et al., Identification of novel knockout targets for improving terpenoids biosynthesis in Saccharomyces cerevisiae. PLoS One. Nov. 11, 2014;9(11):e112615. doi: 10.1371/journal.pone.0112615.
Takahashi et al., Metabolic engineering of sesquiterpene metabolism in yeast. Biotechnol Bioeng. May 1, 2007;97(1):170-81. doi: 10.1002/bit.21216.
Vickers et al., Recent advances in synthetic biology for engineering isoprenoid production in yeast. Curr Opin Chem Biol. Oct. 2017;40:47-56. doi: 10.1016/j.cbpa.2017.05.017. Epub Jun. 14, 2017.
Wang et al., Dekkera bruxellensis, a beer yeast that specifically bioconverts mogroside extracts into the intense natural sweetener siamenoside I. Food Chem. Mar. 15, 2019;276:43-49. doi: 10.1016/j.foodchem.2018.09.163. Epub Sep. 29, 2018.
Xu et al., Emerging molecular biology tools and strategies for engineering natural product biosynthesis. Metab Eng Commun. Jun. 2020;10:e00108. doi: 10.1016/j.mec.2019.e00108. Epub Nov. 9, 2019.
Yee et al., Engineered mitochondrial production of monoterpenes in Saccharomyces cerevisiae. Metab Eng. Sep. 2019;55:76-84. doi: 10.1016/j.ymben.2019.06.004. Epub Jun. 19, 2019.
U.S. Appl. No. 17/924,659, filed Nov. 10, 2022, Boucher et al.
EP 19882275.1, Jul. 22, 2022, Extended European Search Report.
Extended European Search Report for Application No. EP 19882275.1, mailed Jul. 22, 2022.
[No Author Listed], Mogroside. Wikipedia. Internet Archive Wayback Machine. Jan. 9, 2014 Accessible at: https://web.archive.org/web/20140109130110/http://en.wikipedia.org/wiki/Mogroside. Retrieved on Apr. 14, 2016. 1 page.
[No Author Listed], UDP-glycosyltransferases signature. Prosite Accession No. PS00375. Oct. 2, 20175. Internet Archive Wayback Machine. Accessible at https://web.archive.org/web/20171103215026/https:/prosite.expasy.org/PS00375. Retrieved on Nov. 3, 2017. 2 pages.
Arnesen et al., Yarrowia lipolytica Strains Engineered for the Production of Terpenoids. Front Bioeng Biotechnol. Aug. 14, 2020;8:945. doi: 10.3389/fbioe.2020.00945.
Badouin et al., The sunflower genome provides insights into oil metabolism, flowering and Asterid evolution. Nature. Jun. 1, 2017;546(7656):148-152. doi: 10.1038/nature22380. Epub May 22, 2017.
Bowles et al., Glycosyltransferases: managers of small molecules. Curr Opin Plant Biol. Jun. 2005;8(3):254-63. doi: 10.1016/j.pbi.2005.03.007.
Bröker et al., Upregulating the mevalonate pathway and repressing sterol synthesis in Saccharomyces cerevisiae enhances the production of triterpenes. Appl Microbiol Biotechnol. Aug. 2018;102(16):6923-6934. doi: 10.1007/s00253-018-9154-7. Epub Jun. 15, 2018.
Chaturvedula et al., Additional cucurbitane glycosides from Siraitia grosvenorii. IOSR J Pharmacy (IOSRPHR). Jul. 2012;2(4):7-12. doi: 10.9790/3013-2420712.
Chaturvedula et al., Cucurbitane glycosides from Siraitia grosvenorii. J Carbohydrate Chem. Jun. 27, 2011;30(1):16-26. doi: 10.1080/07328303.2011.583511.
Cheng et al., Araport11: a complete reannotation of the Arabidopsis thaliana reference genome. Plant J. Feb. 2017;89(4):789-804. doi: 10.1111/tpj.13415. Epub Feb. 10, 2017.
Chiu et al., Biotransformation of mogrosides from Siraitia grosvenorii Swingle by Saccharomyces cerevisiae. J Agric Food Chem. Jul. 24, 2013;61(29):7127-34. doi: 10.1021/jf402058p. Epub Jul. 11, 2013.
Culp et al. Hidden antibiotics in actinomycetes can be identified by inactivation of gene clusters for common antibiotics. Nat Biotechnol. Oct. 2019;37(10):1149-1154. doi: 10.1038/s41587-019-0241-9. Epub Sep. 9, 2019.
Czajka et al., Engineering the oleaginous yeast Yarrowia lipolytica to produce the aroma compound β-ionone. Microb Cell Fact. Sep. 1, 2018;17(1):136. doi: 10.1186/s12934-018-0984-x.
Dai et al., Functional Characterization of Cucurbitadienol Synthase and Triterpene Glycosyltransferase Involved in Biosynthesis of Mogrosides from Siraitia grosvenorii. Plant Cell Physiol. Jun. 2015;56(6):1172-82. doi: 10.1093/pcp/pcv043. Epub Mar. 9, 2015.
Davidovich-Rikanati et al., Recombinant yeast as a functional tool for understanding bitterness and cucurbitacin biosynthesis in watermelon (Citrullus spp.). Yeast. Jan. 2015;32(1):103-14. doi: 10.1002/yea.3049. Epub Nov. 20, 2014.
Dewitte et al., Screening of recombinant glycosyltransferases reveals the broad acceptor specificity of stevia UGT-76G1. J Biotechnol. Sep. 10, 2016;233:49-55. doi: 10.1016/j.jbiotec.2016.06.034. Epub Jul. 1, 2016.
Furubayashi et al., A high-throughput colorimetric screening assay for terpene synthase activity based on substrate consumption. PLoS One. Mar. 28, 2014;9(3):e93317. doi: 10.1371/journal.pone.0093317.
Gardner et al., An oxysterol-derived positive signal for 3-hydroxy-3-methylglutaryl-CoA reductase degradation in yeast. J Biol Chem. Mar. 23, 2001;276(12):8681-94. doi: 10.1074/jbc.M007888200. Epub Dec. 27, 2000.
Gou et al., Cytochrome b5 Is an Obligate Electron Shuttle Protein for Syringyl Lignin Biosynthesis in Arabidopsis. Plant Cell. Jun. 2019;31(6):1344-1366. doi: 10.1105/tpc.18.00778. Epub Apr. 8, 2019.
Grubbs et al., Large-Scale Bioinformatics Analysis of Bacillus Genomes Uncovers Conserved Roles of Natural Products in Bacterial Physiology. mSystems. Nov. 14, 2017;2(6):e00040-17. doi: 10.1128/mSystems.00040-17.
Guo et al., Protein tolerance to random amino acid change. Proc Natl Acad Sci U S A. Jun. 22, 2004;101(25):9205-10. doi: 10.1073/pnas.0403255101. Epub Jun. 14, 2004.
Guo et al., Transcriptome sequencing and comparative analysis of cucumber flowers with different sex types. BMC Genomics. Jun. 17, 2010;11:384. doi: 10.1186/1471-2164-11-384.
Hamburger et al., Plant P450s as versatile drivers for evolution of species-specific chemical diversity. Philos Trans R Soc Lond B Biol Sci. Jan. 6, 2013;368(1612):20120426. doi: 10.1098/rstb.2012.0426.
Huang et al., The genome of the cucumber, Cucumis sativus L. Nat Genet. Dec. 2009;41(12):1275-81. doi: 10.1038/ng.475. Epub Nov. 1, 2009.
International Brachypodium Initiative, Genome sequencing and analysis of the model grass Brachypodium distachyon. Nature. Feb. 11, 2010;463(7282):763-8. doi: 10.1038/nature08747.
International Peach Genome Initiative et al., The high-quality draft genome of peach (Prunus persica) identifies unique patterns of genetic diversity, domestication and genome evolution. Nat Genet. May 2013;45(5):487-94. doi: 10.1038/ng.2586. Epub Mar. 24, 2013.
Itkin et al., The biosynthetic pathway of the nonsugar, high-intensity sweetener mogroside V from Siraitia grosvenorii. Proc Natl Acad Sci U S A. Nov. 22, 2016;113(47):E7619-E7628 and Supplemental Material. doi: 10.1073/pnas.1604828113. Epub Nov. 7, 2016. Erratum in: Proc Natl Acad Sci U S A. Apr. 2, 2018. 79 pages.
Jia et al., A minor, sweet cucurbitane glycoside from Siraitia grosvenorii. Nat Prod Commun. Jun. 2009;4(6):769-72.
Jones et al., UGT73C6 and UGT78D1, glycosyltransferases involved in flavonol glycoside biosynthesis in Arabidopsis thaliana. J Biol Chem. Nov. 7, 2003;278(45):43910-8. doi: 10.1074/jbc.M303523200. Epub Aug. 4, 2003.
Kang et al., Genome sequence of mungbean and insights into evolution within Vigna species. Nat Commun. Nov. 11, 2014;5:5443. doi: 10.1038/ncomms6443.
Kasai et al., Sweet cucurbitane glycosides from fruits of Siraitia siamensis (chi-zi luo-han-guo), a Chinese folk medicine. Agricultural and biological chemistry. Dec. 1, 1989;53(12):3347-9.
Kim et al., In silico identification of metabolic engineering strategies for improved lipid production in Yarrowia lipolytica by genome-scale metabolic modeling. Biotechnol Biofuels. Jul. 24, 2019;12:187. doi: 10.1186/s13068-019-1518-4.
Kirby et al., Engineering triterpene production in Saccharomyces cerevisiae-β-amyrin synthase from Artemisia annua. FEBS J. Apr. 2008;275(8):1852-9. doi: 10.1111/j.1742-4658.2008.06343.x. Epub Mar. 8, 2008.
Kumar, S., Engineering cytochrome P450 biocatalysts for biotechnology, medicine and bioremediation. Expert Opin Drug Metab Toxicol. Feb. 2010;6(2):115-31. doi: 10.1517/17425250903431040.
Leushkin et al., The miniature genome of a carnivorous plant Genlisea aurea contains a low number of genes and short non-coding sequences. BMC Genomics. Jul. 15, 2013;14:476. doi: 10.1186/1471-2164-14-476.
Li et al., Cucurbitane glycosides from unripe fruits of Lo Han Kuo (Siraitia grosvenori). Chem Pharm Bull (Tokyo). Oct. 2006;54(10):1425-8.
Li et al., Phylogenetic analysis of the UDP-glycosyltransferase multigene family of Arabidopsis thaliana. J Biol Chem. Feb. 9, 2001;276(6):4338-43. doi: 10.1074/jbc.M007447200. Epub Oct. 20, 2000.
Li et al., Production of Rebaudioside A from Stevioside Catalyzed by the Engineered Saccharomyces cerevisiae. Appl Biochem Biotechnol. Apr. 2016;178(8):1586-98. doi: 10.1007/s12010-015-1969-4. Epub Jan. 6, 2016.
Li et al., RNA-Seq improves annotation of protein-coding genes in the cucumber genome. BMC Genomics. Nov. 2, 2011;12:540. doi: 10.1186/1471-2164-12-540.
Li et al., Systematic exploration of essential yeast gene function with temperature-sensitive mutants. Nat Biotechnol. Apr. 2011;29(4):361-7. doi: 10.1038/nbt.1832. Epub Mar. 27, 2011.
Lim et al., Arabidopsis glycosyltransferases as biocatalysts in fermentation for regioselective synthesis of diverse quercetin glucosides. Biotechnol Bioeng. Sep. 5, 2004;87(5):623-31. doi: 10.1002/bit.20154.
Lim et al., Identification of glucosyltransferase genes involved in sinapate metabolism and lignin synthesis in Arabidopsis. J Biol Chem. Feb. 9, 2001;276(6):4344-9. doi: 10.1074/jbc.M007263200. Epub Oct. 20, 2000.
Lin et al., Sequence and analysis of chromosome 2 of the plant Arabidopsis thaliana. Nature. Dec. 16, 1999;402(6763):761-8. doi: 10.1038/45471.
Lodeiro et al., A putative precursor of isomalabaricane triterpenoids from lanosterol synthase mutants. Org Lett. Feb. 2, 2006;8(3):439-42. doi: 10.1021/01052725j.
Lorenz et al., Regulation of ergosterol biosynthesis and sterol uptake in a sterol-auxotrophic yeast. J Bacteriol. Aug. 1987;169(8):3707-11. doi: 10.1128/jb.169.8.3707-3711.1987.
Matsumoto et al., Minor cucurbitane-glycosides from fruits of Siraitia grosvenori (Cucurbitaceae). Chemical and pharmaceutical bulletin. Jul. 25, 1990;38(7):2030-2.
Mengin-Lecreulx et al., The murG gene of Escherichia coli codes for the UDP-N-acetylglucosamine: N-acetylmuramyl-(pentapeptide) pyrophosphoryl-undecaprenol N-acetylglucosamine transferase involved in the membrane steps of peptidoglycan synthesis. J Bacteriol. Aug. 1991;173(15):4625-36. doi: 10.1128/jb.173.15.4625-4636.1991.
Myburg et al., The genome of Eucalyptus grandis. Nature. Jun. 19, 2014;510(7505):356-62. doi: 10.1038/nature13308. Epub Jun. 11, 2014.
Oliaro-Bosso et al., Access of the substrate to the active site of squalene and oxidosqualene cyclases: comparative inhibition, site-directed mutagenesis and homology-modelling studies. Biochem Soc Trans. Nov. 2005;33(Pt 5):1202-5. doi: 10.1042/BST20051202.
Patro et al., Salmon provides fast and bias-aware quantification of transcript expression. Nat Methods. Apr. 2017;14(4):417-419. doi: 10.1038/nmeth.4197. Epub Mar. 6, 2017.
Poppenberger et al., Detoxification of the Fusarium mycotoxin deoxynivalenol by a UDP-glucosyltransferase from Arabidopsis thaliana. J Biol Chem. Nov. 28, 2003;278(48):47905-14. doi: 10.1074/jbc.M307552200. Epub Sep. 11, 2003.
Poppenberger et al., Heterologous expression of Arabidopsis UDP-glucosyltransferases in Saccharomyces cerevisiae for production of zearalenone-4-O-glucoside. Appl Environ Microbiol. Jun. 2006;72(6):4404-10. doi: 10.1128/AEM.02544-05.
Qiao et al., Modification of isoprene synthesis to enable production of curcurbitadienol synthesis in Saccharomyces cerevisiae. J Ind Microbiol Biotechnol. Feb. 2019;46(2):147-157. doi: 10.1007/s10295-018-2116-3. Epub Dec. 10, 2018.
Qin et al., Whole-genome sequencing of cultivated and wild peppers provides insights into Capsicum domestication and specialization. Proc Natl Acad Sci U S A. Apr. 8, 2014;111(14):5135-40. doi: 10.1073/pnas.1400975111. Epub Mar. 3, 2014.
Ren et al., An integrated genetic and cytogenetic map of the cucumber genome. PLoS One. Jun. 4, 2009;4(6):e5795. doi: 10.1371/journal.pone.0005795.
Richman et al., Functional genomics uncovers three glucosyltransferases involved in the synthesis of the major sweet glucosides of Stevia rebaudiana. Plant J. Jan. 2005;41(1):56-67. doi: 10.1111/j.1365-313X.2004.02275.x.
Saito et al., The flavonoid biosynthetic pathway in Arabidopsis: structural and genetic diversity. Plant Physiol Biochem. Nov. 2013;72:21-34. doi: 10.1016/j.plaphy.2013.02.001. Epub Feb. 16, 2013.
Schaffer et al., Cloning and targeted gene disruption of EXGI, encoding exo-β 1, 3-glucanase, in the phytopathogenic fungus Cochliobolus carbonum. Appl Environ Microbiol. Feb. 1994;60(2):594-8. doi: 10.1128/aem.60.2.594-598.1994.
Schmidt et al., Identification of a Saccharomyces cerevisiae glucosidase that hydrolyzes flavonoid glucosides. Appl Environ Microbiol. Mar. 2011;77(5):1751-7. doi: 10.1128/AEM.01125-10. Epub Jan. 7, 2011.
Seki et al., Functional annotation of a full-length Arabidopsis cDNA collection. Science. Apr. 5, 2002;296(5565):141-5. doi: 10.1126/science.1071006. Epub Mar. 21, 2002.
Seki et al., Licorice β-amyrin 11-oxidase, a cytochrome P450 with a key role in the biosynthesis of the triterpene sweetener glycyrrhizin. Proc Natl Acad Sci U S A. Sep. 16, 2008;105(37):14204-9. doi: 10.1073/pnas.0803876105. Epub Sep. 8, 2008.
Seki et al., Triterpene functional genomics in licorice for identification of CYP72A154 involved in the biosynthesis of glycyrrhizin. Plant Cell. Nov. 2011;23(11):4112-23. doi: 10.1105/tpc.110.082685. Epub Nov. 29, 2011.
Shang et al., Engineering Plant Cytochrome P450s for Enhanced Synthesis of Natural Products: Past Achievements and Future Perspectives. Plant Commun. Dec. 3, 2019;1(1):100012. doi: 10.1016/j.xplc.2019.100012.
Shao et al., Crystal structures of a multifunctional triterpene/flavonoid glycosyltransferase from Medicago truncatula. Plant Cell. Nov. 2005;17(11):3141-54. doi: 10.1105/tpc.105.035055. Epub Oct. 7, 2005.
Sharma et al., Genome-wide identification and tissue-specific expression analysis of UDP-glycosyltransferases genes confirm their abundance in Cicer arietinum (Chickpea) genome. PLoS One. Oct. 7, 2014;9(10):e109715. doi: 10.1371/journal.pone.0109715.
Shibuya et al., Cucurbitadienol synthase, the first committed enzyme for cucurbitacin biosynthesis, is a distinct enzyme from cycloartenol synthase for phytosterol biosynthesis. Tetrahedron. Aug. 9, 2004;60(33):6995-7003.
Silva-Junior et al., Genome assembly of the Pink Ipê (Handroanthus impetiginosus, Bignoniaceae), a highly valued, ecologically keystone Neotropical timber forest tree. Gigascience. Jan. 1, 2018;7(1):1-16. doi: 10.1093/gigascience/gix125.
Slotte et al., The Capsella rubella genome and the genomic consequences of rapid mating system evolution. Nat Genet. Jul. 2013;45(7):831-5. doi: 10.1038/ng.2669. Epub Jun. 9, 2013.
Takase et al., Control of the 1,2-rearrangement process by oxidosqualene cyclases during triterpene biosynthesis. Org Biomol Chem. Jul. 14, 2015;13(26):7331-6. doi: 10.1039/c5ob00714c. Epub Jun. 10, 2015.
Tang et al., An efficient approach to finding Siraitia grosvenorii triterpene biosynthetic genes by RNA-seq and digital gene expression analysis. BMC Genomics. Jul. 5, 2011;12:343. doi: 10.1186/1471-2164-12-343.
Tian et al., Comparative Genomics Analysis of Streptomyces Species Reveals Their Adaptation to the Marine Environment and Their Diversity at the Genomic Level. Front Microbiol. Jun. 27, 2016;7:998. doi: 10.3389/fmicb.2016.00998.
Tomato Genome Consortium, The tomato genome sequence provides insights into fleshy fruit evolution. Nature. May 30, 2012;485(7400):635-41. doi: 10.1038/nature11119.
Van Velzen et al., Parallel loss of symbiosis genes in relatives of nitrogen-fixing non-legume Parasponia. bioRxiv preprint. Jul. 28, 2017. doi: https://doi.org/10.1101/169706.
Wang et al., [Downregulation of lanosterol synthase gene expression by antisense RNA technology in Saccharomyces cerevisiae]. Yao Xue Xue Bao. Jan. 2015;50(1):118-22. Chinese. Abstract.
Wang et al., Hyperproduction of β-Glucanase Exg1 Promotes the Bioconversion of Mogrosides in Saccharomyces cerevisiae Mutants Defective in Mannoprotein Deposition. J Agric Food Chem. Dec. 2, 2015;63(47):10271-9. doi: 10.1021/acs.jafc.5b03909. Epub Nov. 19, 2015.
Wang et al., Production of bioactive ginsenosides Rh2 and Rg3 by metabolically engineered yeasts. Metab Eng. May 2015;29:97-105. doi: 10.1016/j.ymben.2015.03.003. Epub Mar. 11, 2015.
Weiner et al., Rapid motif-based prediction of circular permutations in multi-domain proteins. Bioinformatics. Apr. 1, 2005;21(7):932-7. doi: 10.1093/bioinformatics/bti085.
Xia et al., Improved de novo genome assembly and analysis of the Chinese cucurbit Siraitia grosvenorii, also known as monk fruit or luo-han-guo. Gigascience Database. May 30, 2018:Supporting Information. doi: http://dx.doi.org/10.5524/100452. Accessible at http://gigadb.org/dataset/view/id/100452. 7 pages.
Xia et al., Improved de novo genome assembly and analysis of the Chinese cucurbit Siraitia grosvenorii, also known as monk fruit or luo-han-guo. Gigascience. Jun. 8, 2018;7(6):giy067. doi: 10.1093/gigascience/giy067. 9 pages.
Xiong et al., Biosynthesis of triterpene glycoside in Lo Han Kuo. J Guangdong Pharma Uni. 2011;27(5):544-5.
Yu et al., Circular permutation: a different way to engineer enzyme structure and function. Trends Biotechnol. Jan. 2011;29(1):18-25. doi: 10.1016/j.tibtech.2010.10.004. Epub Nov. 17, 2010.
Zhang et al., Oxidation of Cucurbitadienol Catalyzed by CYP87D18 in the Biosynthesis of Mogrosides from Siraitia grosvenorii. Plant Cell Physiol. May 2016;57(5):1000-7 and Supplemental Material. doi: 10.1093/pcp/pcw038. Epub Feb. 21, 2016. 17 pages.
Zwick et al., Genomic characterization of the Bacillus cereus sensu lato species: backdrop to the evolution of Bacillus anthracis. Genome Res. Aug. 2012;22(8):1512-24. doi: 10.1101/gr.134437.111. Epub May 29, 2012.
Altschul et al., Basic local alignment search tool. J Mol Biol. Oct. 5, 1990;215(3):403-10. doi: 10.1016/S0022-2836(05)80360-2.
Altschul et al., Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res. Sep. 1, 1997;25(17):3389-402. doi: 10.1093/nar/25.17.3389.
Karlin et al., Applications and statistics for multiple high-scoring segments in molecular sequences. Proc Natl Acad Sci USA. Jun. 15, 1993;90(12):5873-7. doi: 10.1073/pnas.90.12.5873.
Karlin et al., Methods for assessing the statistical significance of molecular sequence features by using general scoring schemes. Proc Natl Acad Sci USA. Mar. 1990;87(6):2264-8. doi: 10.1073/pnas.87.6.2264.
Liu et al., Characterization of a thermostable β-glucosidase from Aspergillus fumigatus Z5, and its functional expression in Pichia pastoris X33. Microb Cell Fact. Feb. 17, 2012;11:25. doi: 10.1186/1475-2859-11-25.
Lodeiro et al., Enzyme redesign: two mutations cooperate to convert cycloartenol synthase into an accurate lanosterol synthase. J Am Chem Soc. Oct. 19, 2005;127(41):14132-3. doi: 10.1021/ja053791j.
Needleman et al., A general method applicable to the search for similarities in the amino acid sequence of two proteins. J Mol Biol. Mar. 1970;48(3):443-53. doi: 10.1016/0022-2836(70)90057-4.
Sievers et al., Fast, scalable generation of high-quality protein multiple sequence alignments using Clustal Omega. Mol Syst Biol. Oct. 11, 2011;7:539. doi: 10.1038/msb.2011.75.
Smith et al., Identification of common molecular subsequences. J Mol Biol. Mar. 25, 1981;147(1):195-7. doi: 10.1016/0022-2836(81)90087-5.
Suzuki et al., Lanosterol synthase in dicotyledonous plants. Plant Cell Physiol. May 2006;47(5):565-71. doi: 10.1093/pcp/pcj031. Epub Mar. 10, 2006.
Wishart et al., A single mutation converts a novel phosphotyrosine binding domain into a dual-specificity phosphatase. J Biol Chem. Nov. 10, 1995;270(45):26782-5. doi: 10.1074/jbc.270.45.26782.
Witkowski et al., Conversion of a β-ketoacyl synthase to a malonyl decarboxylase by replacement of the active-site cysteine with glutamine. Biochemistry. Sep. 7, 1999;38(36):11643-50. doi: 10.1021/bi990993h. Epub Aug. 18, 1999.
Related Publications (1)
Number Date Country
20210403921 A1 Dec 2021 US
Provisional Applications (1)
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62758474 Nov 2018 US