Structure and function of a spectrin-like regulator of bacterial cytokinesis.
Structure and function of a spectrin-like regulator of bacterial cytokinesis.
复制标题
DOI：
10.1038/ncomms6421
复制
发表时间：
2014-11-18
影响因子：
16.6
通讯作者：
Lewis RJ
中科院分区：
文献类型：
--
作者：
Cleverley RM;Barrett JR;Baslé A;Bui NK;Hewitt L;Solovyova A;Xu ZQ;Daniel RA;Dixon NE;Harry EJ;Oakley AJ;Vollmer W;Lewis RJ
细菌细胞分裂是由分子机器（分裂体）促进的，该分子机器在分裂细胞的细胞中部组装。微管蛋白同源物 FtsZ 形成的细胞因子 Z 环受到多种因素的调节，包括分裂体成分 EzrA。在这里，我们描述了 EzrA 60 kDa 胞质结构域的结构，该结构域包含不寻常的三螺旋束的五个线性重复。 EzrA 结构弯曲成半圆形，使该蛋白质能够在 N 端和 C 端与相邻的膜结合分裂体成分相互作用。我们还确定了 EzrA 上 FtsZ 的至少两个结合位点，并绘制了负责调节 FtsZ 组装的 EzrA 区域。各个重复序列及其线性组织与真核生物中将肌动蛋白丝连接到膜的血影蛋白同源，因此我们认为 EzrA 是细菌血影蛋白家族的创始成员。 EzrA 调节 FtsZ 的聚合，FtsZ 是一种微管蛋白样蛋白，也是 Z 环的主要成分，可驱动细菌中的细胞分裂。在这里，作者描述了 EzrA 的晶体结构，并证明它与真核血影蛋白具有相同的结构和功能特性。
Bacterial cell division is facilitated by a molecular machine—the divisome—that assembles at mid-cell in dividing cells. The formation of the cytokinetic Z-ring by the tubulin homologue FtsZ is regulated by several factors, including the divisome component EzrA. Here we describe the structure of the 60-kDa cytoplasmic domain of EzrA, which comprises five linear repeats of an unusual triple helical bundle. The EzrA structure is bent into a semicircle, providing the protein with the potential to interact at both N- and C-termini with adjacent membrane-bound divisome components. We also identify at least two binding sites for FtsZ on EzrA and map regions of EzrA that are responsible for regulating FtsZ assembly. The individual repeats, and their linear organization, are homologous to the spectrin proteins that connect actin filaments to the membrane in eukaryotes, and we thus propose that EzrA is the founding member of the bacterial spectrin family. EzrA regulates the polymerization of FtsZ, a tubulin-like protein and main component of the Z-ring, which drives cell division in bacteria. Here the authors describe the crystal structure of EzrA and demonstrate that it shares structural and functional properties with eukaryotic spectrins.