伯克氏菌中新型非核糖体脂肽的定向挖掘与途径解析

非核糖体脂肽是由非核糖体多肽合成酶（NRPS）指导合成的，在其聚肽链N端带有脂肪酸链的一类化合物，脂肪酸链可进入细菌细胞膜的磷脂双分子层，因此通常具有广泛的生物活性。脂肪酸链与聚肽链氨基的缩合反应通常是由特殊的起始缩合（Cs）结构域负责完成，因此识别Cs结构域可定向挖掘非核糖体脂肽。基因组序列分析显示伯克氏菌基因组中仍有大量编码非核糖体脂肽的NRPS基因簇有待挖掘。基于前期在伯克氏菌中建立的高效基因组编辑技术和基因簇异源表达体系，本项目拟系统分析伯克氏菌中带有Cs结构域的NRPS基因簇，优选具有潜在生物活性的新型脂肽基因簇；综合利用本源菌基因簇激活和异源表达策略挖掘新型非核糖体脂肽，鉴定其化学结构，探讨其生物功能；利用基因敲除结合酶催化反应解析新颖脂肽的生物合成途径。本项目有助于深入挖掘伯克氏菌合成次级代谢产物的能力，为开发具有自主知识产权的新型药物提供物质基础，积累基因簇资源和催化元件。

Nonribosomal lipopeptides are non-ribosomal peptide synthetases (NRPSs) directed linear or cyclic oligopeptides containing a lipid tail on the N-terminus of the peptide. The lipid chain can enter the phospholipid bilayer of bacterial cell membranes, which endows lipopeptides a wide range of biological activities. The condensation reaction of fatty acid chain and polypeptide chain is usually catalyzed by a special starter condensation (Cs) domain, so the recognizing Cs domain can direct the targeted mining of nonribosomal lipopeptides. Genomic sequence analysis shows that there are still a large number of NRPS gene clusters encoding nonribosomal lipopeptides in the genomes of Burkholderiales to be tapped. Based on our previous efforts on the efficient genome editing technology and gene cluster heterologous expression system of biosynthetic gene clusters in Burkholderiales species, this project intends to systematically analyze the NRPS gene cluster with the Cs domain in Burkholderiales species to prioritize biosynthetic gene clusters encoding novel nonribosomal lipopeptides with potential bioactivities; comprehensively use the homologous activation and heterologous expression strategies to activate nonribosomal lipopeptides, identify their chemical structure, and explore their biological functions; harness gene knockout and enzyme-catalyzed reactions to elucidate the biosynthetic pathways of novel lipopeptides. This project is conducive to deeply mine the biosynthetic potential of Burkholderiales to synthesize secondary metabolites, and provide materials, gene cluster resources and catalytic elements for the development of new drugs with independent intellectual property rights.