Characterizing CmodAA-Containing Biosynthetic Pathways of Nonribosomal Peptides

在化学系生命过程中的化学项目的支持下，查佩尔山的北卡罗来纳州大学的李波正在研究非核糖体肽生物合成中脱氢氨基酸的形成。非核糖体肽是一类重要的生物和工业天然产物，它们由微生物使用称为非核糖体肽合成酶（NRPS）的酶组装线合成。脱氢氨基酸对于含有它们的天然产物的生物活性至关重要;然而，NRPS如何整合这些氨基酸直到最近才进行实验研究。PI将研究NRPS如何使用生物化学，结构和生物信息学方法将脱氢氨基酸整合到各种天然产物中。这项工作有望促进对天然产物生物合成的分子细节的理解，特别是这里正在研究的新型生物膜形成天然产物。 拟议的研究将允许研究生获得生物和天然产物化学的专门培训，并为本科生提供暑期研究机会。该研究项目旨在了解天然产物中α，β-脱氢氨基酸的生物合成，该生物合成由NRPS缩合结构域（CmodAA）的独特亚组催化。该研究将集中在双环生物碱，包括吡咯烷和环氨基甲酸酯，表现出不同的生物活性。在这些天然产物的生物合成中，将表征CmodAA结构域和黄素依赖性单加氧酶的功能。一个未经表征的CmodAA含有生物合成基因簇将进行调查，以确定潜在的新的天然产物。这个项目将使用生物化学，结构生物学，合成化学和生物信息学的方法相结合。作为一个重要的科学更广泛的影响，这项研究预计将使脱氢氨基酸纳入非核糖体肽的工程生物合成和合成生物学，在一般情况下，这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

With the support of the Chemistry in Life Processes program in the Division of Chemistry, Bo Li of the University of North Carolina at Chapel Hill is studying the formation of dehydroamino acids in the biosynthesis of nonribosomal peptides. Nonribosomal peptides are a major class of biologically and industrially important natural products and they are synthesized by microorganisms using enzyme assembly lines known as nonribosomal peptide synthetases (NRPSs). Dehydroamino acids are critical for the biological activities of the natural products that contain them; however, how NRPSs incorporate these amino acids had not been experimentally studied until recently. The PI will study how NRPSs integrate dehydroamino acids into diverse natural products using biochemical, structural, and bioinformatic approaches. The work is expected to advance understanding of the molecular details of the biosynthesis of natural products, particularly the novel biofilm-forming natural products under study here. The proposed study will allow graduate students to acquire specialize training in biological and natural product chemistry and provide summer research opportunities to undergraduates. This research project seeks to understand the biosynthesis of α,β-dehydroamino acids in natural products, which is catalyzed by a unique subgroup of NRPS condensation domains (CmodAA). The research will focus on bicyclic alkaloids, including pyrrolizidines and cyclocarbamates that exhibit diverse bioactivities. In the biosynthesis of these natural products, the function of CmodAA domains and flavin-dependent monooxygenases will be characterized. An uncharacterized CmodAA-containing biosynthetic gene cluster will be investigated to identify potentially novel natural products. This project will use a combination of approaches in biochemistry, structural biology, synthetic chemistry, and bioinformatics. As an important scientific broader impact, this research is expected to enable the incorporation of dehydroamino acids into nonribosomal peptides for engineered biosynthesis and synthetic biology, in general.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.