Characterizing CmodAA-Containing Biosynthetic Pathways of Nonribosomal Peptides

在化学系生命过程化学项目的支持下，北卡罗来纳大学教堂山分校的伯利正在研究非核糖体多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，它们是由微生物利用被称为非核糖体肽合成酶(NRPS)的酶装配线合成的。脱氢氨基酸对含有脱氢氨基酸的天然产物的生物活性至关重要；然而，直到最近才对NRPS如何结合这些氨基酸进行了实验研究。PI将研究NRPS如何使用生化、结构和生物信息学方法将脱氢氨基酸整合到不同的天然产品中。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形成生物膜的新型天然产物。这项拟议的研究将允许研究生获得生物和天然产品化学方面的专门培训，并为本科生提供暑期研究机会。本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，该合成是由NRPS缩合结构域的一个独特亚基(CmodAA)催化的。这项研究将集中在双环生物碱，包括具有不同生物活性的吡咯里齐啶和环氨基甲酸酯。在这些天然产物的生物合成中，CmodAA结构域和黄素依赖的单加氧酶的功能将被表征。将对含有CmodAA的未知生物合成基因簇进行研究，以确定潜在的新天然产物。这个项目将结合生物化学、结构生物学、合成化学和生物信息学的方法。作为一项重要的更广泛的科学影响，这项研究有望将脱氢氨基酸纳入非核糖体多肽中，用于工程生物合成和合成生物学。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

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.