Positioning cell wall synthetic complexes by the bacterial morphogenetic proteins MreB and MreD
Positioning cell wall synthetic complexes by the bacterial morphogenetic proteins MreB and MreD
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DOI：
10.1111/j.1365-2958.2010.07108.x
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发表时间：
2010-05-01
影响因子：
3.6
通讯作者：
Gober, James W.
中科院分区：
文献类型：
--
作者：
White, Courtney L.;Kitich, Aleksandar;Gober, James W.
在新月形Caulobacter crescent中，肌动蛋白同源物MreB的完整缆索对于MurG的适当空间定位是必需的，而MurG催化了肽聚糖前体合成的最后一步。类似地，在外周质中，MreC控制青霉素结合蛋白的空间方向和一种裂解转糖基化酶。我们现在已经发现，MreB电缆是组织其他几种细胞质小鼠生物合成酶（如MraY， MurB, MurC， MurE和MurF）所必需的。我们还发现这些蛋白采用与MurG类似的亚细胞定位模式，表明存在细胞骨架依赖的相互作用。通过广泛的双杂交分析，我们现在已经生成了细菌形态发生复合物组分的综合相互作用图。在细胞质中，该复合物含有小鼠生物合成酶和形态发生蛋白，包括RodA、RodZ和MreD。我们发现，整体膜蛋白MreD对侧肽聚糖合成至关重要，它与前体合成酶MurG和MraY相互作用，此外，还决定了MreB的定位。我们的研究结果表明，MreB和MreD相互依赖的定位功能在空间上组织了肽聚糖前体合成蛋白复合物，这是均匀细胞形状繁殖和催化高效肽聚糖合成所必需的。
P>In Caulobacter crescentus, intact cables of the actin homologue, MreB, are required for the proper spatial positioning of MurG which catalyses the final step in peptidoglycan precursor synthesis. Similarly, in the periplasm, MreC controls the spatial orientation of the penicillin binding proteins and a lytic transglycosylase. We have now found that MreB cables are required for the organization of several other cytosolic murein biosynthetic enzymes such as MraY, MurB, MurC, MurE and MurF. We also show these proteins adopt a subcellular pattern of localization comparable to MurG, suggesting the existence of cytoskeletal-dependent interactions. Through extensive two-hybrid analyses, we have now generated a comprehensive interaction map of components of the bacterial morphogenetic complex. In the cytosol, this complex contains both murein biosynthetic enzymes and morphogenetic proteins, including RodA, RodZ and MreD. We show that the integral membrane protein, MreD, is essential for lateral peptidoglycan synthesis, interacts with the precursor synthesizing enzymes MurG and MraY, and additionally, determines MreB localization. Our results suggest that the interdependent localization of MreB and MreD functions to spatially organize a complex of peptidoglycan precursor synthesis proteins, which is required for propagation of a uniform cell shape and catalytically efficient peptidoglycan synthesis.