title: Biosynthesis of 3'-deoxy-carbamoylkanamycin C in a Streptomyces tenebrarius mutant strain by tacB gene disruption.
abstract: Streptomyces tenebrarius H6 mainly produces three kinds of antibiotics: apramycin, carbamoyltobramycin and some carbamoylkanamycin B. In our present study, a dehydrogenase gene tacB in the tobramycin biosynthetic gene cluster was disrupted by in-frame deletion. The result of TLC bio-autograph analysis demonstrated the disruption mutant strain produced apramycin and a new antibiotic. The new antibiotic was identified as 3'-deoxy-carbamoylkanamycin C by MS and NMR analysis after isolation and purification. The disruption mutant was restored to produce carbamoyltobramycin in a complementation experiment by the intact tacB gene. Our studies suggested that the tacB gene encodes a 6'-dehydrogenase, which reduces the 6'-hydroxyl group of paromamine to a keto group, thus facilitating the transfer of an aminogroup to form neamine. This study is the first report on the generation of a tobramycin derivative by gene engineering, and will contribute to clarify the complete biosynthetic pathway of tobramycin.
authors.affiliation: The School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang, Liaoning, China.
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Yu
authors.forename: Xifan
authors.initials: X
authors.lastname: Hou
authors.forename: Xianpu
authors.initials: X
authors.lastname: Ni
authors.forename: Huanzhang
authors.initials: H
authors.lastname: Xia
mesh_terms: D000617:Aminoglycosides / Q000096:biosynthesis* / Q000737:chemistry / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000737:chemistry / Q000494:pharmacology; D007612:Kanamycin / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000737:chemistry / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D016364:Reading Frames / Q000235:genetics; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism
chemical_list: C529996:3'-deoxy-carbamoylkanamycin C; D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D007612:Kanamycin