title: Characterization of tailoring genes involved in the modification of geldanamycin polyketide in Streptomyces hygroscopicus JCM4427.
abstract: Geldanamycin and its analogs are important anticancer agents that inhibit the newly targeted, heat-shock protein (Hsp) 90, which is a chaperone protein in eukaryotic cells. To resolve which geldanamycin biosynthetic genes are responsible for particular post-polyketide synthase (PKS) processing steps and in which order the reactions occur, we individually inactivated candidate genes in Streptomyces hygroscopicus subsp. duamyceticus JCM4427, and isolated and elucidated the structures of intermediates from each mutant. The results indicated that gel7 governs at least one of the benzoquinone ring oxidation steps. In addition, gel16 was found to be involved in double-bond formation between C-4 and C-5 of 4,5-dihydrogeldanamycin, which confirmed our previous findings that this double bond reduced during the post-PKS modification of the polyketide assembly. In addition, pro-geldanamycin, which does not possess a double bond at C-4/5, was purified from the gel7 and 8 double-gene-inactivated mutant.
authors.affiliation: Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea.
authors.forename: Jin-Chul
authors.initials: JC
authors.lastname: Shin
authors.forename: Zhu
authors.initials: Z
authors.lastname: Na
authors.forename: Dong-Ho
authors.initials: DH
authors.lastname: Lee
authors.forename: Won-Cheol
authors.initials: WC
authors.lastname: Kim
authors.forename: Kyeong
authors.initials: K
authors.lastname: Lee
authors.forename: Yue-Mao
authors.initials: YM
authors.lastname: Shen
authors.forename: Sang-Gi
authors.initials: SG
authors.lastname: Paik
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Hong
authors.forename: Jung-Joon
authors.initials: JJ
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism*; D016227:Benzoquinones / Q000378:metabolism*; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D047029:Lactams, Macrocyclic / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family; D016254:Mutagenesis, Insertional; D048630:Polyketide Synthases / Q000378:metabolism*; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D016227:Benzoquinones; D047029:Lactams, Macrocyclic; D048630:Polyketide Synthases; C001277:geldanamycin