title: Identification and cloning of the gene involved in the final step of chlortetracycline biosynthesis in Streptomyces aureofaciens.
abstract: For chlortetracycline biosynthesis in Streptomyces aureofaciens, the final reduction step is essential to give an antibiotic activity to its intermediate, which is catalyzed by tetracycline dehydrogenase with 7,8-dedimethyl-8-hydroxy-5-deazariboflavin (FO) as a cofactor. We identified and cloned the gene, which is essential for the biosynthesis of 6-demethyltetracycline and participates in the final step of its biosynthesis, from the genomic DNA of the 6-demethyltetracycline producer S. aureofaciens HP77. DNA sequence analysis revealed that the gene (tchA) had an open reading frame of 455 amino acids with an estimated molecular mass of 48.1 kDa. Southern hybridization analysis revealed that the tchA gene was located external to the chlortetracycline biosynthetic gene cluster in the genome. A conserved domain search of protein sequence databases indicated that TchA showed a similarity to FbiB, which is involved in the modification of FO in Mycobacterium bovis.
authors.affiliation: Tokyo Research Laboratories, Kyowa Hakko Kogyo Co., Ltd., Tokyo, Japan. t.nakano@kyowa.co.jp
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Nakano
authors.forename: Koichiro
authors.initials: K
authors.lastname: Miyake
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Endo
authors.forename: Tohru
authors.initials: T
authors.lastname: Dairi
authors.forename: Toru
authors.initials: T
authors.lastname: Mizukami
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Katsumata
mesh_terms: D001483:Base Sequence; D002751:Chlortetracycline / Q000096:biosynthesis*; D003001:Cloning, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D016366:Open Reading Frames; D010088:Oxidoreductases / Q000235:genetics*; D013304:Streptomyces aureofaciens / Q000235:genetics* / Q000378:metabolism
chemical_list: D010088:Oxidoreductases; C021852:tetracycline 5a(11a)dehydrogenase; D002751:Chlortetracycline