Molecular motor tug-of-war regulates elongasome cell wall synthesis dynamics in Bacillus subtilis
Molecular motor tug-of-war regulates elongasome cell wall synthesis dynamics in Bacillus subtilis
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分子运动拔河比赛调节枯草芽孢杆菌细胞壁合成动力学
DOI：
10.1101/2023.05.10.540107
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Middlemiss S
中科院分区：
文献类型：
--
作者：
Middlemiss S
大多数杆状细菌通过将新的细胞壁材料插入细胞侧壁的内表面而伸长。这是由A类青霉素结合蛋白（PBPs）和高度保守的蛋白质复合物，延长酶体，它移动proceptor周围的细胞圆周和插入长聚糖链，作为桶箍样加强结构，从而产生一个杆状细胞。然而，目前仍不清楚如何调节延长体合成动力学和终止事件，以确定这些关键的细胞强化结构的长度。为了解决这个问题，我们开发了一种方法，使用单分子荧光显微镜在枯草芽孢杆菌细胞的整个圆周周围跟踪单个延长酶体复合物长达几分钟。我们发现，B。subtiliselongasome是高度进行性的，并且进行性合成事件经常被快速逆转或延长的停顿终止。我们发现，细胞水平的RodA调节延长体的持续性，逆转和暂停。我们的单分子数据，再加上随机模拟，表明延长体动力学和持续合成能力的调节分子马达拔河比赛之间的几个，可能是两个，相对取向的肽聚糖合成复合物与MreB丝。总之，这些结果表明，分子马达拔河是一个关键的调节器的延长体动力学在B。枯草芽孢杆菌，其可能还通过调节延长体持续合成能力来调节细胞形状。
Most rod-shaped bacteria elongate by inserting new cell wall material into the inner surface of the cell sidewall. This is performed by class A penicillin binding proteins (PBPs) and a highly conserved protein complex, the elongasome, which moves processively around the cell circumference and inserts long glycan strands that act as barrel-hoop-like reinforcing structures, thereby giving rise to a rod-shaped cell. However, it remains unclear how elongasome synthesis dynamics and termination events are regulated to determine the length of these critical cell-reinforcing structures. To address this, we developed a method to track individual elongasome complexes around the entire circumference ofBacillus subtiliscells for minutes-long periods using single-molecule fluorescence microscopy. We found that theB. subtiliselongasome is highly processive and that processive synthesis events are frequently terminated by rapid reversal or extended pauses. We found that cellular levels of RodA regulate elongasome processivity, reversal and pausing. Our single-molecule data, together with stochastic simulations, show that elongasome dynamics and processivity are regulated by molecular motor tug-of-war competition between several, likely two, oppositely oriented peptidoglycan synthesis complexes associated with the MreB filament. Altogether these results demonstrate that molecular motor tug-of-war is a key regulator of elongasome dynamics inB. subtilis, which likely also regulates the cell shape via modulation of elongasome processivity.