Peptidoglycan synthesis drives a single population of septal cell wall synthases during division in Bacillus subtilis
Peptidoglycan synthesis drives a single population of septal cell wall synthases during division in Bacillus subtilis
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DOI：
10.1038/s41564-024-01650-9
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发表时间：
2024-03-13
影响因子：
28.3
通讯作者：
Holden，Seamus
中科院分区：
文献类型：
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作者：
Whitley，Kevin D.;Grimshaw，James;Holden，Seamus
细菌细胞分裂需要分裂体复合物合成间隔肽聚糖（sPG）。基本微管蛋白同源物FtsZ的跑步机已被牵连在间隔收缩，但其确切的作用仍不清楚。在这里，我们使用活细胞单分子成像的分裂体转肽酶PBP2B调查sPG合成动力学在枯草芽孢杆菌。与之前的模型相反，我们观察到单个群体的渐进移动的PBP 2B分子，其运动由肽聚糖合成驱动，与FtsZ跑步机无关。然而，尽管PBP2B和FtsZ的异步运动，PBP2B的持续合成能力对FtsZ的连续研磨的部分依赖性进行了观察。此外，通过单分子计数实验，我们提供的证据表明，分裂体合成复合物是多聚体。我们的研究结果支持一个模型为B。subtilisdivision，其中多聚体合成复合物遵循依赖于sPG合成的单一轨道，其活性和动力学与FtsZ跑步机是异步的。
Bacterial cell division requires septal peptidoglycan (sPG) synthesis by the divisome complex. Treadmilling of the essential tubulin homologue FtsZ has been implicated in septal constriction, though its precise role remains unclear. Here we used live-cell single-molecule imaging of the divisome transpeptidase PBP2B to investigate sPG synthesis dynamics inBacillus subtilis. In contrast to previous models, we observed a single population of processively moving PBP2B molecules whose motion is driven by peptidoglycan synthesis and is not associated with FtsZ treadmilling. However, despite the asynchronous motions of PBP2B and FtsZ, a partial dependence of PBP2B processivity on FtsZ treadmilling was observed. Additionally, through single-molecule counting experiments we provide evidence that the divisome synthesis complex is multimeric. Our results support a model forB. subtilisdivision where a multimeric synthesis complex follows a single track dependent on sPG synthesis whose activity and dynamics are asynchronous with FtsZ treadmilling.