title: Identification and characterization of wblA-dependent tmcT regulation during tautomycetin biosynthesis in Streptomyces sp. CK4412.
abstract: Tautomycetin (TMC) is an unusual linear polyketide compound esterified with a cyclic anhydride. It exhibits novel activated T cell-specific immunosuppressant as well as anti-cancer activities. Previously, we isolated and characterized the entire TMC biosynthetic gene cluster from Streptomyces sp. CK4412, including a TMC pathway-specific gene, tmcN, the over-expression of which led to a significant increase in TMC productivity. In addition, we also reported that WblA acts as a global down-regulator of antibiotic biosynthesis through pathway-specific regulation in Streptomyces species. Here, we confirm that TmcT acts as another TMC pathway-specific regulator within the TMC biosynthetic cluster. Specifically, tmcT deletion resulted in the complete loss of TMC production, whereas complementation with a tmcT-carrying integrative plasmid significantly restored TMC biosynthesis. We also identified a 0.39kb wblA ortholog (named wblA(tmc)) from Streptomyces sp. CK4412 via genomic DNA library screening that showed 96% amino acid identity compared to a previously-known S. coelicolor wblA. Targeted gene disruption of wblA(tmc) in Streptomyces sp. CK4412 exhibited approximately 3-fold higher TMC productivity than that in the wild-type strain. Moreover, transcription analyses of the TMC biosynthetic and regulatory genes revealed that the expression of tmcT was strongly down-regulated by wblA(tmc). These results imply that the TMC biosynthetic regulation network is controlled by two pathway-specific positive regulator, WblA(tmc)-dependent TmcT as well as WblA(tmc)-independent TmcN in Streptomyces sp. CK4412.
authors.affiliation: Department of Biological Engineering, Inha University, Incheon, Republic of Korea.
authors.forename: Ji-Hye
authors.initials: JH
authors.lastname: Nah
authors.forename: Shin-Hae
authors.initials: SH
authors.lastname: Park
authors.forename: Hye-Mi
authors.initials: HM
authors.lastname: Yoon
authors.forename: Si-Sun
authors.initials: SS
authors.lastname: Choi
authors.forename: Chul-Hoon
authors.initials: CH
authors.lastname: Lee
authors.forename: Eung-Soo
authors.initials: ES
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D003198:Computer Simulation; D005663:Furans; D015964:Gene Expression Regulation, Bacterial; D055786:Gene Knockout Techniques; D008055:Lipids / Q000096:biosynthesis* / Q000235:genetics; D053858:Metabolic Networks and Pathways; D008969:Molecular Sequence Data; D005810:Multigene Family; D016415:Sequence Alignment; D015398:Signal Transduction; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D005663:Furans; D008055:Lipids; D014157:Transcription Factors; C058744:tautomycetin