Characterization of a Novel Mutation in the Overlap of tlyA and ppnK Involved in Capreomycin Resistance in Mycobacterium
Characterization of a Novel Mutation in the Overlap of tlyA and ppnK Involved in Capreomycin Resistance in Mycobacterium
复制标题
分枝杆菌卷曲霉素抗性中 tlyA 和 ppnK 重叠的新突变的表征
DOI：
10.1002/iub.1277
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发表时间：
2014-06-01
期刊：
影响因子：
4.6
通讯作者：
Xie, Jianping
中科院分区：
文献类型：
--
作者：
Du, Qinglin;Long, Quanxin;Xie, Jianping
卷曲霉素（CAP）是治疗耐多药结核病的重要二线药物。为进一步阐明CAP的耐药机制，利用Tn 5转座子构建耻垢分枝杆菌转座子突变体库，筛选CAP耐药菌株。分离并鉴定了一株CAP抗性增加4倍的突变体（命名为C4）。Tn 5被插入到MSMEG_0841中，这是一个注释的假基因。然而，敲除证明MSMEG_0841不负责CAP抗性。我们进一步对C4全基因组进行测序，发现tlyA和ppnK之间的重叠区域存在A到G的取代，这导致上游tlyA的终止密码子突变和下游ppnK的T2 A突变。重叠区的突变可能导致两个基因的功能障碍。tlyA是参与CAP作用的已知基因。ppnK在大肠杆菌和M.包皮环切术赋予对CAP敏感性。综上所述，我们的研究发现了一个新的突变参与CAP耐药。VC 2014 IUBMB Life，66（6）：405-414，2014
Capreomycin (CAP) is an important second-line drug for multidrug-resistant tuberculosis. To further define the drug resistance mechanism of CAP, a Mycobacterium smegmatis transposon mutant library was constructed using Tn5 transposon for screening isolates with enhanced CAP resistance. A mutant (named C4) with fourfold increased CAP resistance was isolated and characterized. Tn5 was found to be inserted into MSMEG_0841, an annotated pseudogene. However, knockout demonstrated that MSMEG_0841 was not responsible for CAP resistance. We further sequenced the whole genome of C4 and found an A to G substitution in the overlap region between tlyA and ppnK, which leads a stop codon mutation in upstream tlyA and a T2A mutation in downstream ppnK. Mutation in the overlap might confer the dysfuction of both genes. tlyA is a known gene involved in CAP action. Overexpression of ppnK in both Escherichia coli and M. smegmatis confer subtle susceptible to CAP. Taken together, our study found that a novel mutation involved in CAP resistance. VC 2014 IUBMB Life, 66(6): 405-414, 2014