Elucidation of structure-function of unique bacterial flagellar stator complex from Bacillus spp.

首先，我们确定了枯草芽孢杆菌鞭毛马达是一种混合马达，它通过单一分子机制同时利用H+和Na+离子动力进行旋转。接下来，利用定点诱变技术鉴定了枯草芽孢杆菌MotA和MotP亚基中第二和第三跨膜胞质环区之间的关键带电氨基酸残基。此外，我们还从嗜碱芽孢杆菌中发现了一种新型鞭毛马达，在升高的K+或Rb+浓度下刺激游泳速度。这是首次报道同时使用K+和Rb+作为偶联离子的鞭毛马达。

At first, we identified that the flagellar motor of B. subtilis was a hybrid motor and it rotated by using both ion motive forces, H+ and Na+, by a single molecular mechanism. Next, the critical charged amino acid residues between the second and third transmembrane cytoplasmic loop region in MotA and MotP subunits of B. subtilis were identified by using site-directed mutagenesis. Moreover, we identified a novel type flagellar motor from alkaliphilic Bacillus alcalophilus which stimulates swimming speed under elevated K+ or Rb+ concentrations. This is the first report that describes aflagellar motor that can use both K+ and Rb+ as coupling ions.