Sarpeptins A and B, Lipopeptides Produced by Streptomyces sp. KO-7888 Overexpressing a Specific SARP Regulator

Whole genome analysis of Streptomyces sp. KO-7888 has revealed various pathway-specific transcriptional regulatory genes associated with silent biosynthetic gene clusters. A Streptomyces antibiotic regulatory protein gene, speR, located adjacent to a novel nonribosomal peptide synthetase (NRPS) gene cluster, was overexpressed in the wild-type strain. The resulting recombinant strain of Streptomyces sp. KO-7888 produced two new lipopeptides, sarpeptins A and B. Their structures were elucidated by high-resolution electrospray ionization mass spectrometry, NMR analysis, and the advanced Marfey’s method. The distinct modular sections of the corresponding NRPS biosynthetic gene cluster were characterized, and the assembly line for production of the lipopeptide chain was proposed.