志贺菌福氏2a301菌株torA基因改变的研究

The change of torA gene of Shigella flexneri 2a301 strain

目的 探讨志贺菌福氏 2a30 1菌株torA基因的改变以及与TorA(trimethylamineN oxideTMAOreductase ,三甲胺N 氧化物还原酶 )转运相关的TAT分泌系统的存在。方法 利用酶活性检测和Westernblot方法来验证志贺菌福氏 2a30 1测序菌株torA基因发生的碱基置换 ,并且利用正常大肠杆菌中torA基因的克隆转化来研究TAT分泌系统的存在。结果 实验表明志贺菌福氏2a30 1菌株不具有TorA酶活性 ,不表达TorA蛋白 ,和序列分析的结果相符 ;但是 ,将torA基因克隆子转化入 30 1菌株后 ,转化子获得了TorA酶活性 ,表达了TorA蛋白。结论 在志贺菌福氏 2a30 1菌株中torA基因发生了改变 ,但具有完整的TAT分泌途径 ,可以转运蛋白。

Objective To study the change of torA gene and TAT secretion system related to TorA(trimethylamine N oxide TMAO reductase) translocation in Shigella flexneri 2a301 strain. Methods The detection of the enzyme activity and Western blot were used and transformed the clone of torA gene of E.coli into Shigella flexneri 2a301. Results No TMAO reductase activity and protein expression of TorA were observed in S.flexneri 2a301, that is also proved by sequence analysis. However, when S.flexneri 2a301 was obtained the cloned intact gene from E.coli by transformation, the enzyme activity was restored and protein expression of TorA was detected. Conclusion Our results showed that torA gene in S.flexneri 2a301 is changed, but the TAT system can translocate the protein.