Assembly mechanism of a supramolecular MS-ring complex to initiate bacterial flagellar biogenesis in Vibrio species.
Assembly mechanism of a supramolecular MS-ring complex to initiate bacterial flagellar biogenesis in Vibrio species.
复制标题
超分子 MS 环复合物的组装机制启动弧菌物种中细菌鞭毛的生物发生。
DOI：
10.1128/jb.00236-20
复制
发表时间：
2020
影响因子：
3.2
通讯作者：
Homma M.
中科院分区：
文献类型：
--
作者：
Terashima H;Hirano K;Inoue Y;Tokano T;Kawamoto A;Kato T;Yamaguchi E;Namba K;Uchihashi T;Kojima S;Homma M.
细菌鞭毛是负责运动的细胞器，并且具有包括转子和定子的旋转马达。鞭毛的生物发生是由MS-环的组装启动的，MS-环是一种嵌入细胞质膜的超分子复合物。MS环由几十个跨膜FliF蛋白拷贝组成，是转子的一部分，是一个重要的核心结构。在某些物种中，鞭毛的数量和位置由FlhF和FlhG蛋白控制。然而，目前还不清楚的因素启动MS环组装或在此过程中的FlhF/FlhG的贡献。在这里，我们表明，FlhF和C-环组件，FliG，促进弧菌MS环的形成。当VibrioFliF单独在大肠杆菌细胞中表达时，很少发生MS环形成，表明MS环组装需要其他因子。因此，我们研究了在MS环组装中FlhF是否辅助FliF。我们发现，FlhF允许绿色荧光蛋白（GFP）融合的FliF定位在aVibriocell中的细胞极，这表明它增加了FliF在极的局部浓度。FliF与FlhF在E. coli细胞中，有效地形成MS环，表明FlhF在某种程度上有助于MS环的形成。分离的MS-环结构与沙门氏菌FliF形成的MS-环结构相似。有趣的是，FliG促进MS环的形成，表明FliF和FliG有助于彼此组装成MS环和C环。这项研究有助于理解MS环组装背后的机制，使用适当的空间/时间regulations.IMPORTANCEFlagellar的形成是由FliF蛋白组装成MS环复合物，这是嵌入在细胞质膜。适当的空间/时间控制MS环的形成是重要的细菌鞭毛的形态发生。在这里，我们专注于VibrioFliF到MS环的组装机制。FlhF是鞭毛数量和位置的正调节因子，在细胞极募集FliF分子并促进MS环形成。FliG还促进MS-环形成。我们的研究表明，这些因素控制鞭毛的生物发生在弧菌启动MS环组装。此外，这也意味着鞭毛的生物发生是一个复杂的系统与某些基因的表达，蛋白质的定位，和一个超分子复合体组装。
The bacterial flagellum is an organelle responsible for motility and has a rotary motor comprising the rotor and the stator. Flagellar biogenesis is initiated by the assembly of the MS-ring, a supramolecular complex embedded in the cytoplasmic membrane. The MS-ring consists of a few dozen copies of the transmembrane FliF protein and is an essential core structure that is a part of the rotor. The number and locations of the flagella are controlled by the FlhF and FlhG proteins in some species. However, there is no clarity on the factors initiating MS-ring assembly or on the contributions of FlhF/FlhG to this process. Here, we show that FlhF and a C-ring component, FliG, facilitate Vibrio MS-ring formation. WhenVibrioFliF alone was expressed in Escherichia coli cells, MS-ring formation rarely occurred, indicating a requirement of other factors for MS-ring assembly. Consequently, we investigated if FlhF aided FliF in MS-ring assembly. We found that FlhF allowed green fluorescent protein (GFP)-fused FliF to localize at the cell pole in aVibriocell, suggesting that it increases local concentration of FliF at the pole. When FliF was coexpressed with FlhF in E. coli cells, the MS-ring was effectively formed, indicating that FlhF somehow contributes to MS-ring formation. The isolated MS-ring structure was similar to that of the MS-ring formed by Salmonella FliF. Interestingly, FliG facilitates MS-ring formation, suggesting that FliF and FliG assist in each other’s assembly into the MS-ring and C-ring. This study aids in understanding the mechanism behind MS-ring assembly using appropriate spatial/temporal regulations.IMPORTANCEFlagellar formation is initiated by the assembly of the FliF protein into the MS-ring complex, which is embedded in the cytoplasmic membrane. The appropriate spatial/temporal control of MS-ring formation is important for the morphogenesis of the bacterial flagellum. Here, we focus on the assembly mechanism ofVibrioFliF into the MS-ring. FlhF, a positive regulator of the number and location of flagella, recruits the FliF molecules at the cell pole and facilitates MS-ring formation. FliG also facilitates MS-ring formation. Our study showed that these factors control flagellar biogenesis inVibrioby initiating the MS-ring assembly. Furthermore, it also implies that flagellar biogenesis is a sophisticated system linked with the expression of certain genes, protein localization, and a supramolecular complex assembly.