NSF Award
2325341
Specialized metabolites are not only the spice of life, they mediate nearly all organismal interactions with the environment. Due to their importance, this proposed work aims to understand how the >200,000 chemicals produced by plants and microorganisms evolved. Knowledge of the historical genetic mechanisms allowing for existing metabolites to be produced should allow for the generation of novel metabolites by protein engineering for applications in agriculture, medicine, bioengineering and pharmaceuticals. In order to achieve these research goals, the next generation of diverse scientists at different stages of development will be trained and collect data. At least 100 undergraduate students will be engaged in authentic research experiences that generate novel data so that their findings related to protein evolution and specialized metabolite biosynthesis can be published in peer-reviewed journals. This experience is expected to increase the probability of student recruitment into scientific research careers.<br/><br/>The origins of genomic complexity are unclear but at least partly depend on gene duplication to generate multigene families. This project will investigate the factors that promote multigene family functional diversification after gene duplication, a topic of broad applicability to the thousands of enzymes involved in reactions required for life. To do this, the SABATH enzyme family of methyltransferases, which produce critical molecules for plant development and defense, will be studied. Ancestral Sequence Resurrection will be employed to directly study the ancestral enzymes that gave rise to modern-day enzymes. First, >10,000 enzyme assays will be performed to determine whether protein functional divergence is asymmetrical throughout enzyme family diversification by resurrecting ancient pre- and post-duplication enzymes. Second, the hypothesis that two descendant genes are better than one ancestral gene in terms of biochemical function will also be tested. To do this, the amount of biochemical products produced by pre- and post-duplication enzymes will be measured. Third, ancestral protein crystal structures will be generated for multiple ancestral and descendant enzymes in this family and analyzed in a comparative context to gain insight into active site configurations concomitant with evolutionary changes in enzyme substrate preferences.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
