Nakano Tetsuo, Miyake Koichiro, Endo Hirofumi, Dairi Tohru, Mizukami Toru, Katsumata Ryoichi
Tokyo Research Laboratories, Kyowa Hakko Kogyo Co., Ltd., Tokyo, Japan.
Biosci Biotechnol Biochem. 2004 Jun;68(6):1345-52. doi: 10.1271/bbb.68.1345.
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.
对于金色链霉菌中氯四环素的生物合成，最终还原步骤对于赋予其中间体抗生素活性至关重要，该步骤由四环素脱氢酶以7,8-二去甲基-8-羟基-5-去氮核黄素（FO）作为辅因子催化。我们从6-去甲基四环素产生菌金色链霉菌HP77的基因组DNA中鉴定并克隆了该基因，它对于6-去甲基四环素的生物合成至关重要，并参与其生物合成的最后一步。DNA序列分析表明，该基因（tchA）具有一个455个氨基酸的开放阅读框，估计分子量为48.1 kDa。Southern杂交分析表明，tchA基因位于基因组中氯四环素生物合成基因簇之外。蛋白质序列数据库的保守结构域搜索表明，TchA与FbiB相似，FbiB参与牛分枝杆菌中FO的修饰。
