title: Exploring Peptide Ligase Orthologs in Actinobacteria-Discovery of Pseudopeptide Natural Products, Ketomemicins.
abstract: 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.
authors.affiliation: Graduate School of Engineering, Hokkaido University , Sapporo, Hokkaido 060-8628, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ogasawara
authors.affiliation: Graduate School of Engineering, Hokkaido University , Sapporo, Hokkaido 060-8628, Japan.
authors.forename: Junpei
authors.initials: J
authors.lastname: Kawata
authors.affiliation: Graduate School of Engineering, Hokkaido University , Sapporo, Hokkaido 060-8628, Japan.
authors.forename: Motoyoshi
authors.initials: M
authors.lastname: Noike
authors.affiliation: Graduate School of Engineering, Hokkaido University , Sapporo, Hokkaido 060-8628, Japan.
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Satoh
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo , Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Furihata
authors.affiliation: Graduate School of Engineering, Hokkaido University , Sapporo, Hokkaido 060-8628, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Dairi
mesh_terms: D039903:Actinobacteria / Q000235:genetics* / Q000378:metabolism; D019295:Computational Biology; D005798:Genes, Bacterial; D005810:Multigene Family; D009842:Oligopeptides / Q000096:biosynthesis* / Q000737:chemistry; D010453:Peptide Synthases / Q000737:chemistry* / Q000302:isolation & purification; D013237:Stereoisomerism
chemical_list: D009842:Oligopeptides; D010453:Peptide Synthases