Reconstitution of polythioamide antibiotic backbone formation reveals unusual thiotemplated assembly strategy
Reconstitution of polythioamide antibiotic backbone formation reveals unusual thiotemplated assembly strategy
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DOI：
10.1073/pnas.1918759117
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发表时间：
2020-04-21
影响因子：
11.1
通讯作者：
Hertweck, Christian
中科院分区：
文献类型：
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作者：
Dunbar, Kyle L.;Dell, Maria;Hertweck, Christian
Closthioamide（CTA）是一种罕见的含硫代酰胺的非核糖体肽，是专性厌氧细菌中描述的少数次级代谢产物之一。虽然最近发现了负责CTA生产的生物合成基因簇和催化硫掺入的硫代酰胺合成酶，但肽骨架组装的逻辑仍然是一个谜。在这里，通过使用体外生物化学测定，我们证明了CTA的酰胺骨架组装在一个不寻常的thiotemplated途径，涉及木瓜蛋白酶样半胱氨酸蛋白酶家族的转酰化成员和一个迭代作用的ATP抓蛋白的合作。使用ATP抓蛋白作为生物信息学处理，我们确定了数百个这样的thiotemplated但非核糖体肽合成酶（NRPS）独立的生物合成基因簇在不同的细菌门。本文提供的数据不仅阐明了CTA生物合成的途径，而且为发现由非经典生物合成途径产生的其他次级代谢产物提供了基础。
Closthioamide (CTA) is a rare example of a thioamide-containing nonribosomal peptide and is one of only a handful of secondary metabolites described from obligately anaerobic bacteria. Although the biosynthetic gene cluster responsible for CTA production and the thioamide synthetase that catalyzes sulfur incorporation were recently discovered, the logic for peptide backbone assembly has remained a mystery. Here, through the use of in vitro biochemical assays, we demonstrate that the amide backbone of CTA is assembled in an unusual thiotemplated pathway involving the cooperation of a transacylating member of the papain-like cysteine protease family and an iteratively acting ATP-grasp protein. Using the ATP-grasp protein as a bioinformatic handle, we identified hundreds of such thiotemplated yet nonribosomal peptide synthetase (NRPS)-independent biosynthetic gene clusters across diverse bacterial phyla. The data presented herein not only clarify the pathway for the biosynthesis of CTA, but also provide a foundation for the discovery of additional secondary metabolites produced by noncanonical biosynthetic pathways.