Identification and cloning of the gene involved in the final step of chlortetracycline biosynthesis in Streptomyces aureofaciens.
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.
Nakano
Tetsuo
T
Tokyo Research Laboratories, Kyowa Hakko Kogyo Co., Ltd., Tokyo, Japan. t.nakano@kyowa.co.jp
Miyake
Koichiro
K
Endo
Hirofumi
H
Dairi
Tohru
T
Mizukami
Toru
T
Katsumata
Ryoichi
R
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
D010088:Oxidoreductases; C021852:tetracycline 5a(11a)dehydrogenase; D002751:Chlortetracycline