Quan S, Imai T, Mikami Y, Yazawa K, Dabbs E R, Morisaki N, Iwasaki S, Hashimoto Y, Furihata K
Genetics Department, University of the Witwatersrand, Johannesburg 2050, South Africa.
Antimicrob Agents Chemother. 1999 Jan;43(1):181-4. doi: 10.1128/AAC.43.1.181.
Mycobacterium smegmatis DSM43756 inactivates rifampin, and the inactivated antibiotic product recovered from culture medium was ribosylated on the 23-OH group. To study this process, the gene responsible for the inactivation was expressed at high levels by the lac promoter in Escherichia coli conferring resistance to >500 microg of antibiotic per ml. Cell homogenates generated a novel derivative designated RIP-TAs; in this study, we determined that RIP-TAs is 23-(O-ADP-ribosyl)rifampin. Our results indicated that RIP-TAs is an intermediate in the pathway leading to ribosylated rifampin and that the previously characterized gene encodes a mono(ADP-ribosyl)transferase which, however, shows no sequence similarity to other enzymes of this class.
耻垢分枝杆菌DSM43756可使利福平失活，从培养基中回收的失活抗生素产物在23 - OH基团上发生了核糖基化。为研究此过程，负责失活的基因通过大肠杆菌中的lac启动子高水平表达，赋予每毫升大于500微克抗生素的抗性。细胞匀浆产生了一种名为RIP - TAs的新型衍生物；在本研究中，我们确定RIP - TAs为23 - (O - ADP - 核糖基)利福平。我们的结果表明，RIP - TAs是导致核糖基化利福平的途径中的一个中间体，并且先前鉴定的基因编码一种单(ADP - 核糖基)转移酶，然而，该酶与这类其他酶没有序列相似性。
