Full-length Escherichia coli SecA Dimerizes in a Closed Conformation in Solution as Determined by Cryo-electron Microscopy
Full-length Escherichia coli SecA Dimerizes in a Closed Conformation in Solution as Determined by Cryo-electron Microscopy
复制标题
通过冷冻电子显微镜测定全长大肠杆菌 SecA 在溶液中以闭合构象二聚化
DOI：
10.1074/jbc.c800160200
复制
发表时间：
2008-10-24
影响因子：
4.8
通讯作者：
Sui, Sen-Fang
中科院分区：
文献类型：
--
作者：
Chen, Yong;Pan, Xijiang;Sui, Sen-Fang
SecA是大肠杆菌一般分泌途径的必需组分。然而，SecA的寡聚体结构和SecA在易位过程中的构象变化仍然不清楚。在此我们获得了E.大肠杆菌野生型全长SecA在溶液中通过单粒子冷冻电子显微镜，并确定其寡聚体组织。在这种结构中，SecA作为二聚体出现，其中两个原聚体以反平行模式排列，具有新颖的静电界面，并且两个原聚体都处于闭合构象。这里开发的系统可以提供一个很有前途的技术，研究动态结构变化SecA。
SecA is an obligatory component of the Escherichia coli general secretion pathway. However, the oligomeric structure of SecA and SecA conformational changes during translocation processes are still unclear. Here we obtained the three-dimensional structure of E. coli wild-type full-length SecA in solution by single particle cryo-electron microscopy and determined its oligomeric organization. In this structure, SecA occurs as a dimer in which the two protomers are arranged in an antiparallel mode, with a novel electrostatic interface, and both protomers are in closed conformation. The system developed here may provide a promising technique for studying dynamic structural changes in SecA.