Interaction between FtsW and penicillin-binding protein 3 (PBP3) directs PBP3 to mid-cell, controls cell septation and mediates the formation of a trimeric complex involving FtsZ, FtsW and PBP3 in mycobacteria
Interaction between FtsW and penicillin-binding protein 3 (PBP3) directs PBP3 to mid-cell, controls cell septation and mediates the formation of a trimeric complex involving FtsZ, FtsW and PBP3 in mycobacteria
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DOI：
10.1111/j.1365-2958.2006.05491.x
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发表时间：
2006-12-01
影响因子：
3.6
通讯作者：
Basu, Joyoti
中科院分区：
文献类型：
--
作者：
Datta, Pratik;Dasgupta, Arunava;Basu, Joyoti
在细菌中，细胞壁在分裂位点的生物发生需要青霉素结合蛋白3 (PBP3)（或FtsI）。通过下拉、细菌双杂交和基于肽的相互作用试验，我们提供了证据，证明结核分枝杆菌的FtsW（MTB）通过两个胞质外环与PBP3相互作用。FtsW大环中的Pro（306）和小环中的Pro（386）对这些相互作用至关重要。荧光显微镜显示耻垢分枝杆菌中ftsW的条件沉默阻止了细胞分离和PBP3在细胞中定位。在M.垢垢分枝杆菌中，下拉试验和条件去除FtsW提供的证据表明，分枝杆菌的FtsZ、FtsW和PBP3能够形成三元配合物，其中FtsW作为桥接分子。细菌三杂交分析表明，在结核分枝杆菌中，FtsZ与FtsW胞质c尾的相互作用（分枝杆菌特有）增强了FtsW与PBP3的相互作用。耻垢分枝杆菌的ftsW可以用结核分枝杆菌的ftsW代替。FtsW（MTB）支持褐皮藻中FtsZ-FtsW-PBP3三元配合物的形成。我们的研究结果提出了一种可能性，即在分枝杆菌属中，FtsZ与FtsW的c尾结合可能调节其与PBP3的相互作用，从而潜在地调节间隔肽聚糖的生物发生。
In bacteria, biogenesis of cell wall at the division site requires penicillin-binding protein 3 (PBP3) (or FtsI). Using pull-down, bacterial two-hybrid, and peptide-based interaction assays, we provide evidence that FtsW of Mycobacterium tuberculosis (FtsW(MTB)) interacts with PBP3 through two extracytoplasmic loops. Pro(306) in the larger loop and Pro(386) in the smaller loop of FtsW are crucial for these interactions. Fluorescence microscopy shows that conditional silencing of ftsW in Mycobacterium smegmatis prevents cell septation and positioning of PBP3 at mid-cell. Pull-down assays and conditional depletion of FtsW in M. smegmatis provide evidence that FtsZ, FtsW and PBP3 of mycobacteria are capable of forming a ternary complex, with FtsW acting as a bridging molecule. Bacterial three-hybrid analysis suggests that in M. tuberculosis, the interaction (unique to mycobacteria) of FtsZ with the cytosolic C-tail of FtsW strengthens the interaction of FtsW with PBP3. ftsW of M. smegmatis could be replaced by ftsW of M. tuberculosis. FtsW(MTB) could support formation of the FtsZ-FtsW-PBP3 ternary complex in M. smegmatis. Our findings raise the possibility that in the genus Mycobacterium binding of FtsZ to the C-tail of FtsW may modulate its interactions with PBP3, thereby potentially regulating septal peptidoglycan biogenesis.