Analysis of interaction, ion transport and structural change in a stator complex of bacterial flagellar motor

活动微生物，如细菌和古细菌，通过改变其游泳模式向更喜欢的栖息地迁移来感知和响应细胞外刺激。在这项研究中，我们利用生物物理技术分析了细菌鞭毛马达定子复合物的相互作用、离子传输和结构变化。通过衰减全反射傅里叶变换红外光谱，我们直接观察到Pom/B复合物中Na^+与羧酸盐的结合，包括功能必需残基Asp24 （Sudo et al.2009b, Biochemistry）。我们还证明了Ala39-MotB和Cys31-PomB是离子通量途径的一部分（Sudo et al. 2009，生物物理学），并报道了MotB c端区域的晶体结构（Kojima et al. 2009, Mol.Microbiol.）。此外，我们发现并鉴定了新的受体蛋白（Suzuki et al. 2009, j.l l. biol）。， Sudo et al.2009a, Biochemistry, Yagasaki et al.2010, Biochemistry, Sudo et al. 2011, j.b ol.chem .)。

Motile microorganisms, such as bacteria and archaea, sense and respond to extracellular stimuli by changing their swimming mode to migrate towards more favorite habitats. In this research, we analyzed interaction, ion transport and structural changes in a stator complex of the bacterial flagellar motor using biophysical techniques. By means of attenuated total reflection Fourier-transform infrared spectroscopy, we directly observed binding of Na^+ to carboxylates in the Pom/B complex, including the functionally essential residue Asp24 (Sudo et al.2009b, Biochemistry). We also demonstrated that Ala39-MotB and Cys31-PomB form part of the ion flux pathway (Sudo et al. 2009, Biophysics), and reported the crystal structure of C-terminal region of MotB (Kojima et al. 2009, Mol.Microbiol.). Moreover we found and characterized new receptor proteins (Suzuki et al. 2009, J.Mol.Biol., Sudo et al.2009a, Biochemistry, Yagasaki et al.2010, Biochemistry, Sudo et al. 2011, J.Biol.Chem.).