Exploring Peptide Ligase Orthologs in Actinobacteria—Discovery of Pseudopeptide Natural Products, Ketomemicins

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• 作者：Yasushi Ogasawara ; Junpei Kawata ; Motoyoshi Noike ; Yasuharu Satoh ; Kazuo Furihata ; Tohru Dairi
• 刊名：ACS Chemical Biology
• 出版年：2016
• 出版时间：June 17, 2016
• 年：2016
• 卷：11
• 期：6
• 页码：1686-1692
• 全文大小：352K
• 年卷期：0
• ISSN：1554-8937

文摘

We recently identified a novel peptide ligase (PGM1), an ATP-grasp-ligase, that catalyzes amide bond formation between (S)-2-(3,5-dihydroxy-4-methoxyphenyl)-2-guanidinoacetic acid and ribosomally supplied oligopeptides in pheganomycin biosynthesis. This was the first example of an ATP-grasp-ligase utilizing peptides as nucleophiles. To explore the potential of this type of enzyme, we performed a BLAST search and identified many orthologs. The orthologs of Streptomyces mobaraensis, Salinispora tropica, and Micromonospora sp. were found in similar gene clusters consisting of six genes. To probe the functions of these genes, we heterologously expressed each of the clusters in Streptomyces lividans and detected novel and structurally similar pseudotripeptides in the broth of all transformants. Moreover, a recombinant PGM1 ortholog of Micromonospora sp. was demonstrated to be a novel dipeptide ligase catalyzing amide bond formation between amidino-arginine and dipeptides to yield tripeptides; this is the first report of a peptide ligase utilizing dipeptides as nucleophiles.