Department of Microbiology, Pusan National University, Busan, 609-735, Republic of Korea.
J Microbiol. 2012 Apr;50(2):270-7. doi: 10.1007/s12275-012-2050-4. Epub 2012 Apr 27.
Using yeast two-hybrid assay, we investigated protein-protein interactions between all orthologous histidine kinase (HK)/response regulator (RR) pairs of M. tuberculosis H37Rv and identified potential protein-protein interactions between a noncognate HK/RR pair, DosT/NarL. The protein interaction between DosT and NarL was verified by phosphotransfer reaction from DosT to NarL. Furthermore, we found that the DosT and DosS HKs, which share considerable sequence similarities to each other and form a two-component system with the DosR RR, have different cross-interaction capabilities with NarL: DosT interacted with NarL, while DosS did not. The dimerization domains of DosT and DosS were shown to be sufficient to confer specificity for DosR, and the different cross-interaction abilities of DosS and DosT with NarL were demonstrated to be attributable to variations in the amino acid sequences of the α2-helices of their dimerization domains.
我们利用酵母双杂交实验，研究了结核分枝杆菌 H37Rv 所有直系同源组氨酸激酶 (HK)/反应调节蛋白 (RR) 对之间的蛋白-蛋白相互作用，并鉴定了非同源 HK/RR 对 DosT/NarL 之间的潜在蛋白-蛋白相互作用。DosT 与 NarL 之间的蛋白相互作用通过 DosT 向 NarL 的磷酸转移反应得到验证。此外，我们发现 DosT 和 DosS HKs 彼此具有相当程度的序列相似性，与 DosR RR 形成一个二组分系统，它们与 NarL 的交叉相互作用能力不同：DosT 与 NarL 相互作用，而 DosS 则没有。DosT 和 DosS 的二聚化结构域被证明足以赋予对 DosR 的特异性，并且 DosS 和 DosT 与 NarL 的不同交叉相互作用能力归因于它们二聚化结构域α2-螺旋氨基酸序列的变化。
