Characterization of the Biosynthetic Gene Cluster for Benzoxazole Antibiotics A33853 Reveals Unusual Assembly Logic.
A33853, which shows excellent bioactivity against Leishmania, is a benzoxazole-family compound formed from two moieties of 3-hydroxyanthranilic acid and one 3-hydroxypicolinic acid. In this study, we have identified the gene cluster responsible for the biosynthesis of A33853 in Streptomyces sp. NRRL12068 through genome mining and heterologous expression. Bioinformatics analysis and functional characterization of the orfs contained in the gene cluster revealed that the biosynthesis of A33853 is directed by a group of unusual enzymes. In particular, BomK, annotated as a ketosynthase, was found to catalyze the amide bond formation between 3-hydroxypicolinic and 3-hydroxyanthranilic acid during the assembly of A33853. BomJ, a putative ATP-dependent coenzyme A ligase, and BomN, a putative amidohydrolase, were further proposed to be involved in the benzoxazole formation in A33853 according to gene deletion experiments. Finally, we have successfully utilized mutasynthesis to generate two analogs of A33853, which were reported previously to possess excellent anti-leishmanial activity.
Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University, 185 East Lake Road, Wuhan 430071, P. R. China.
Meinan
M
Lv
Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University, 185 East Lake Road, Wuhan 430071, P. R. China.
Junfeng
J
Zhao
Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University, 185 East Lake Road, Wuhan 430071, P. R. China.
Zixin
Z
Deng
Key Laboratory of Combinatory Biosynthesis and Drug Discovery (Ministry of Education), School of Pharmaceutical Sciences, Wuhan University, 185 East Lake Road, Wuhan 430071, P. R. China. Electronic address: yu_yi@whu.edu.cn.
Yi
Y
Yu
D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000096:biosynthesis*; D001583:Benzoxazoles / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D008969:Molecular Sequence Data; D015394:Molecular Structure; D005810:Multigene Family / Q000235:genetics*; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism
D000900:Anti-Bacterial Agents; D001583:Benzoxazoles; C041570:A 33853