Cloning of separate meilingmycin biosynthesis gene clusters by use of acyltransferase-ketoreductase didomain PCR amplification.

ABSTRACT: Five meilingmycins, A to E, with A as the major component, were isolated from Streptomyces nanchangensis NS3226. Through nuclear magnetic resonance (NMR) characterization, meilingmycins A to E proved to be identical to reported milbemycins alpha11, alpha13, alpha14, beta1, and beta9, respectively. Sequencing of a previously cloned 103-kb region identified three modular type I polyketide synthase genes putatively encoding the last 11 elongation steps, three modification proteins, and one transcriptional regulatory protein for meilingmycin biosynthesis. However, the expected loading module and the first two elongation modules were missing. In meilingmycin, the presence of a methyl group at C-24 and a hydroxyl group at C-25 suggests that the elongation module 1 contains a methylmalonyl-coenzy

SUBMITTER: He Y 

PROVIDER: S-EPMC2869129 | biostudies-literature | 2010 May

REPOSITORIES: biostudies-literature