Protein translocation across the inner membrane of Gram-negative bacteria: the Sec and Tat dependent protein transport pathways
Protein translocation across the inner membrane of Gram-negative bacteria: the Sec and Tat dependent protein transport pathways
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DOI：
10.1016/j.resmic.2013.03.016
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发表时间：
2013-07-01
影响因子：
2.6
通讯作者：
Koch, Hans-Georg
中科院分区：
文献类型：
--
作者：
Kudva, Renuka;Denks, Kaert;Koch, Hans-Georg
革兰氏阴性细菌具有多种蛋白质转运系统，通过该系统，在胞质溶胶中合成的蛋白质被输出到细胞被膜中的目的地或完全分泌到细胞外环境中。内膜（IM）包含三个主要的转运系统，用于含有信号序列的蛋白质的易位和插入：Sec易位子、YidC插入酶和达特系统。异源三聚体SecYEG易位子在膜中形成窄通道，其具有双重功能;它允许未折叠蛋白质易位穿过孔并将α-螺旋蛋白质整合到IM中。YidC插入酶是一种多跨膜蛋白，其在膜蛋白整合期间与SecYEG易位子合作，但也作为独立的插入酶发挥作用。根据需要运输的蛋白质货物的类型，需要信号识别颗粒（SRP），SRP受体，SecA和伴侣蛋白来协调翻译与运输，并靶向和激励不同的运输系统。达特系统由三种膜蛋白（TatA、TatB和TatC）组成，其以仍然未知的方式完成完全折叠的蛋白质和蛋白质复合物的跨膜通过。(C)2013年巴斯德研究所。由Elsevier Masson SAS出版。All rights reserved.
Gram negative bacteria possess a large variety of protein transport systems, by which proteins that are synthesised in the cytosol are exported to destinations in the cell envelope or entirely secreted into the extracellular environment. The inner membrane (IM) contains three major transport systems for the translocation and insertion of signal sequence containing proteins: the Sec translocon, the YidC insertase, and the Tat system. The heterotrimeric SecYEG translocon forms a narrow channel in the membrane that serves a dual function; it allows the translocation of unfolded proteins across the pore and the integration of a-helical proteins into the IM. The YidC insertase is a multi-spanning membrane protein that cooperates with the SecYEG translocon during the integration of membrane proteins but also functions as an independent insertase. Depending upon the type of protein cargo that needs to be transported, the Signal Recognition Particle (SRP), the SRP receptor, SecA and chaperones are required to coordinate translation with transport and to target and energise the different transport systems. The Tat system consists of three membrane proteins (TatA, TatB and TatC) which in a still unknown manner accomplish the transmembrane passage of completely folded proteins and protein complexes. (C) 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.