title: Identification of a gene cluster of biosynthetic genes of rubradirin substructures in S. achromogenes var. rubradiris NRRL3061.
abstract: Rubradirin, an ansamycin antibiotic has been purified from Streptomyces achromogenes var. rubradiris NRRL3061. It consists of four distinct structural moieties, rubransarol, 3-amino-4-hydroxy-coumarin, dihydroxydipicolinic acid, and 2,6-dideoxynitrosugar (DNS). Polymerase chain reaction (PCR) primers were designed based on consensus sequences of dTDP-D-glucose 4,6-dehydratase, one of enzymes involved in the biosynthesis of 2,6-dideoxysugar. A PCR product was obtained from S. achromogenes var. rubradiris. Hybridization of the PCR product to a cosmid library constructed from S. achromogenes genomic DNA has led to the identification of three unlinked regions of DNA. One of three kinds of cosmid clones contains homologues of dTDP-D-glucose 4,6-dehydratase, 3-amino-5-hydroxybenzoic acid (AHBA) synthase, and eryA genes. The size of the gene homologous to eryA is 30 kb, and the AHBA synthase gene homologue resides between the eryA homologous genes. A gene cluster of rubransarol and 2,6-dideoxynitrosugar is around 50 kb. Sequencing of the PCR product from the AHBA synthase gene homologue isolated from S. achromogenes revealed 85% amino acid sequence homology (73/86) with the AHBA synthase from a rifamycin-producer. dTDP-D-glucose 4,6-dehydratase gene homologue was subcloned from one of the isolated cosmid clones and sequenced. It showed 65% homology (43/66) with dTDP-D-glucose 4,6-dehydratase from a streptomycin-producer.
authors.affiliation: Department of Chemistry, SunMoon University, Asan, Korea.
authors.forename: J K
authors.initials: JK
authors.lastname: Sohng
authors.forename: T J
authors.initials: TJ
authors.lastname: Oh
authors.forename: J J
authors.initials: JJ
authors.lastname: Lee
authors.forename: C G
authors.initials: CG
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D062365:Aminobenzoates / Q000378:metabolism; D015139:Blotting, Southern; D003001:Cloning, Molecular; D016384:Consensus Sequence; D017931:DNA Primers; D005798:Genes, Bacterial; D006836:Hydro-Lyases / Q000096:biosynthesis / Q000235:genetics; D062385:Hydroxybenzoates; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000096:biosynthesis / Q000235:genetics; D005810:Multigene Family; D009285:Naphthoquinones / Q000737:chemistry / Q000378:metabolism; D016133:Polymerase Chain Reaction; D013302:Streptomyces / Q000235:genetics*
chemical_list: D062365:Aminobenzoates; D017931:DNA Primers; D062385:Hydroxybenzoates; D009097:Multienzyme Complexes; D009285:Naphthoquinones; C031509:3-amino-5-hydroxybenzoic acid; C002857:rubradirin; D006836:Hydro-Lyases; C022771:dTDPglucose 4,6-dehydratase