%0 Journal Article
%T Accumulation of lankamycin derivative with a branched-chain sugar from a blocked mutant of chalcose biosynthesis in Streptomyces rochei 7434AN4.
%A Zhang M
%A Shuang B
%A Arakawa K
%J Bioorg Med Chem Lett
%V 80
%N 0
%D 01 2023 15
%M 36621553
%F 2.94
%R 10.1016/j.bmcl.2023.129125
%X Lankamycin, a macrolide antibiotic produced by Streptomyces rochei 7434AN4, exhibits a moderate antimicrobial activity and acts as a synergistic pair with carbocyclic antibiotic lankacidin C by binding to the ribosome exit tunnel. Its biosynthetic gene (lkm) cluster (orf24-orf53) is located on the largest plasmid pSLA2-L (210,614 bp). Our group possesses a variety of lankamycin derivatives and macrolide-modification enzymes including P450 enzymes and glycosyltransferases, which may lead to expand the chemical library of bioactive macrolides. Here we constructed a mutant of a 3-ketoreductase gene lkmCVI (orf42) involved in d-chalcose biosynthesis, and its metabolite was isolated and structure-elucidated. Accumulation of novel lankamycin derivative harboring a branched-chain deoxysugar, 5-O-(4',6'-dideoxy-3'-C-acetyl-d-ribo-hexopyranosyl)-3-O-(4″-O-acetyl-l-arcanosyl)-lankanolide, indicated that LkmCVI acts as a gate keeper enzyme for d-chalcose synthesis in lankamycin biosynthesis.