Weak pulling forces exerted on Nin-orientated transmembrane segments during co-translational insertion into the inner membrane of Escherichia coli
Weak pulling forces exerted on Nin-orientated transmembrane segments during co-translational insertion into the inner membrane of Escherichia coli
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DOI：
10.1016/j.febslet.2014.03.050
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发表时间：
2014-05-21
期刊：
影响因子：
3.5
通讯作者：
von Heijne, Gunnar
中科院分区：
文献类型：
--
作者：
Cymer, Florian;Ismail, Nurzian;von Heijne, Gunnar
膜蛋白中的跨膜螺旋（TMH）可以使其N-末端朝向细胞质（N-in）或朝向非细胞质侧（N-out）取向。大多数膜蛋白在Sec-型转座子的辅助下共显性插入膜中。由于N-in-和N-out-取向TMH的最终取向不同，它们在插入过程中也可以与易位子和周围膜不同地相互作用。我们测量了在共翻译插入到大肠杆菌内膜的过程中施加在N-在定向TMHs上的拉力。我们的结果表明，Nin取向的TMH经历较弱的拉力，但保留了先前对于Nout取向的TMH所看到的总体双相力分布（Ismail等人，2012 [1]）。(C)2014年欧洲生物化学学会联合会。Elsevier B. V.出版，保留所有权利。
Transmembrane helices (TMHs) in membrane proteins can be orientated with their N-terminus towards the cytoplasm (N-in), or facing the non-cytoplasmic side (N-out). Most membrane proteins are inserted co-translationally into membranes, aided by Sec-type translocons. Since the final orientation of N-in-and N-out-orientated TMHs differs, they could also interact differently with the translocon and the surrounding membrane during insertion. We measured pulling forces exerted on N-in-orientated TMHs during co-translational insertion into the inner membrane of Escherichia coli. Our results demonstrate that Nin-orientated TMHs experience a weaker pulling force but retain the overall biphasic force profile seen previously for Nout-orientated TMHs (Ismail et al., 2012 [1]). (C) 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.