Liu Xiaolin, Liu Yanan, Johnson Kevin Scot, Dong Xiaoyan, Xie Zhihong
Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China.
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China.
Front Microbiol. 2020 Dec 7;11:585140. doi: 10.3389/fmicb.2020.585140. eCollection 2020.
Chemotaxis is essential for the competitiveness of motile bacteria in complex and harsh environments. The localization of chemotactic proteins in the cell is critical for coordinating a maximal response to chemotactic signals. One chemotaxis protein with a well-defined subcellular localization is the phosphatase CheZ. CheZ localizes to cell poles by binding with CheA in and other enteric bacteria, or binding with a poorly understood protein called ChePep in epsilon-. In alpha-, CheZ lacks CheA-binding sites, and its cellular localization remains unknown. We therefore determined the localization of CheZ in the alpha- ORS571. CheZ, also termed as CheZ was found to be located to cell poles independently of CheA, and we suspect that either the N-terminal helix or the four-helix bundle of CheZ is sufficient to locate to cell poles. We also found a novel motif, AXXFQ, which is adjacent to the phosphatase active motif DXXXQ, which effects the monopolar localization of CheZ. This novel motif consisting of AXXFQ is conserved in CheZ and widely distributed among . Finally, we found that the substitution of phosphatase active site affects the polar localization of CheZ. In total, this work characterized the localization pattern of CheZ containing a novel motif, and we mapped the regions of CheZ that are critical for its polar localization.
趋化性对于运动性细菌在复杂且恶劣环境中的竞争力至关重要。趋化蛋白在细胞内的定位对于协调对趋化信号的最大反应至关重要。一种亚细胞定位明确的趋化蛋白是磷酸酶CheZ。在[具体细菌名称]和其他肠道细菌中，CheZ通过与CheA结合定位于细胞极，或者在ε-细菌中与一种了解较少的名为ChePep的蛋白结合。在α-细菌中，CheZ缺乏CheA结合位点，其细胞定位仍然未知。因此，我们确定了CheZ在α-ORS571中的定位。发现CheZ（也称为CheZ）独立于CheA定位于细胞极，并且我们怀疑CheZ的N端螺旋或四螺旋束足以定位于细胞极。我们还发现了一个新基序AXXFQ，它与磷酸酶活性基序DXXXQ相邻，影响CheZ的单极定位。这个由AXXFQ组成的新基序在CheZ中保守且在[具体细菌群体]中广泛分布。最后，我们发现磷酸酶活性位点的替换影响CheZ的极性定位。总的来说，这项工作描述了含有新基序的CheZ的定位模式，并且我们绘制了CheZ中对其极性定位至关重要的区域。
