革兰氏阴性菌细菌接合系统的结构生物学。

Structural biology of the Gram-negative bacterial conjugation systems.

机构信息

Institute of Structural and Molecular Biology, UCL and Birkbeck, Malet Street, London, WC1E 7HX, UK.

出版信息

Trends Microbiol. 2015 May;23(5):301-10. doi: 10.1016/j.tim.2015.02.012. Epub 2015 Mar 27.

DOI:10.1016/j.tim.2015.02.012

Abstract

Conjugation, the process by which plasmid DNA is transferred from one bacterium to another, is mediated by type IV secretion systems (T4SSs). T4SSs are versatile systems that can transport not only DNA, but also toxins and effector proteins. Conjugative T4SSs comprise 12 proteins named VirB1-11 and VirD4 that assemble into a large membrane-spanning exporting machine. Before being transported, the DNA substrate is first processed on the cytoplasmic side by a complex called the relaxosome. The substrate is then targeted to the T4SS for export into a recipient cell. In this review, we describe the recent progress made in the structural biology of both the relaxosome and the T4SS.

摘要

conjugation，即质粒 DNA 从一种细菌转移到另一种细菌的过程，是由 IV 型分泌系统（T4SSs）介导的。T4SSs 是一种多功能系统，不仅可以运输 DNA，还可以运输毒素和效应蛋白。接合 T4SS 由 12 种蛋白组成，命名为 VirB1-11 和 VirD4，它们组装成一个大型的跨膜输出机器。在被运输之前，DNA 底物首先在细胞质侧被称为“松弛体”的复合物处理。然后，该底物被靶向到 T4SS 以输出到受体细胞中。在这篇综述中，我们描述了松弛体和 T4SS 的结构生物学方面的最新进展。