FtsZ-ZapA-ZapB Interactome of Escherichia coli
FtsZ-ZapA-ZapB Interactome of Escherichia coli
复制标题
DOI：
10.1128/jb.05821-11
复制
发表时间：
2012-01-01
影响因子：
3.2
通讯作者：
Gerdes, Kenn
中科院分区：
文献类型：
--
作者：
Galli, Elisa;Gerdes, Kenn
细菌细胞分裂依赖于Z环的形成和收缩，由称为分裂体的动态蛋白质复合物协调和调节。细胞分裂因子ZapA直接与FtsZ相互作用，从而增加FtsZ原丝缔合和Z环稳定性。在这里，我们研究了ZapB与ZapA的相互作用及其对Z环形成和FtsZ原丝成束的影响。ftsZ 84等位基因编码的FtsZ变体聚合效率低，与zapB无效突变体的组合导致合成缺陷型。ZapA的过量产生导致异常FtsZ螺旋结构的形成和ZapB的离域。ZapB的N-末端对于ZapB-ZapA相互作用是必需的，并且靠近ZapB的N-末端的氨基酸变化表现出与ZapA的相互作用降低。沉降测定表明，ZapB与ZapA强烈相互作用，并在体外降低ZapA与FtsZ的相互作用。由ZapA和ZapB一起形成的结构的形态类似于在CaCl 2（一种已知的ZapB成束剂）存在下由ZapB形成的缆线。体内和体外数据支持ZapA与ZapB强烈相互作用且ZapA-ZapB相互作用优于ZapA-FtsZ的模型。
Bacterial cell division relies on the formation and contraction of the Z ring, coordinated and regulated by a dynamic protein complex called the divisome. The cell division factor ZapA interacts directly with FtsZ and thereby increases FtsZ protofilament association and Z-ring stability. Here, we investigated ZapB interaction with ZapA and its effect on Z-ring formation and FtsZ protofilament bundling. The combination of the ftsZ84 allele that encodes an FtsZ variant that polymerizes inefficiently with a zapB null mutant resulted in a synthetic defective phenotype. Overproduction of ZapA led to the formation of aberrant FtsZ helical structures and delocalization of ZapB. The N-terminal end of ZapB was essential for ZapB-ZapA interaction, and amino acid changes close to the N terminus of ZapB exhibited reduced interaction with ZapA. Sedimentation assays showed that ZapB interacts strongly with ZapA and reduces ZapA's interaction with FtsZ in vitro. The morphology of the structures formed by ZapA and ZapB together was similar to the cables formed by ZapB in the presence of CaCl2, a known ZapB bundling agent. The in vivo and in vitro data support a model in which ZapA interacts strongly with ZapB and the ZapA-ZapB interaction is favored over ZapA-FtsZ.