Spatial arrangement of several flagellins within bacterial flagella improves motility in different environments
Spatial arrangement of several flagellins within bacterial flagella improves motility in different environments
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DOI：
10.1038/s41467-018-07802-w
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发表时间：
2018-12-18
影响因子：
16.6
通讯作者：
Thormann, Kai M.
中科院分区：
文献类型：
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作者：
Kuehn, Marco J.;Schmidt, Felix K.;Thormann, Kai M.
细菌鞭毛是由鞭毛蛋白组成的螺旋状蛋白质纤维，赋予许多细菌运动能力。在所有有鞭毛的物种中，约一半的物种基因组包含不止一个鞭毛蛋白基因，其原因大多不明。在此我们表明，在腐败希瓦氏菌的极生鞭毛中，两种鞭毛蛋白（FlaA和FlaB）在空间上呈特定排列，靠近马达处FlaA含量更丰富，而在鞭毛丝的其余部分则是FlaB。对游动轨迹的观察和数值模拟表明，与单鞭毛蛋白丝的突变体相比，这种分段在一系列环境条件下提高了运动能力。特别是，它促进了螺旋状运动，这增强了细胞在受阻环境中的扩散。类似机制可能适用于其他细菌物种，并可能解释了维持多种鞭毛蛋白以形成鞭毛丝的原因。
Bacterial flagella are helical proteinaceous fibers, composed of the protein flagellin, that confer motility to many bacterial species. The genomes of about half of all flagellated species include more than one flagellin gene, for reasons mostly unknown. Here we show that two flagellins (FlaA and FlaB) are spatially arranged in the polar flagellum of Shewanella putrefaciens, with FlaA being more abundant close to the motor and FlaB in the remainder of the flagellar filament. Observations of swimming trajectories and numerical simulations demonstrate that this segmentation improves motility in a range of environmental conditions, compared to mutants with single-flagellin filaments. In particular, it facilitates screw-like motility, which enhances cellular spreading through obstructed environments. Similar mechanisms may apply to other bacterial species and may explain the maintenance of multiple flagellins to form the flagellar filament.