Molecular code for transmembrane-helix recognition by the Sec61 translocon
Molecular code for transmembrane-helix recognition by the Sec61 translocon
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DOI：
10.1038/nature06387
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发表时间：
2007-12-13
期刊：
影响因子：
64.8
通讯作者：
von Heijne, Gunnar
中科院分区：
文献类型：
--
作者：
Hessa, Tara;Meindl-Beinker, Nadja M.;von Heijne, Gunnar
整合膜蛋白中的跨膜α-螺旋被协同识别，并通过Sec 61转位子插入内质网膜。一个完整的定量描述这种现象，连接氨基酸序列的膜插入效率，仍然缺乏。在这里，使用在狗胰腺粗微粒体的存在下的模型蛋白的体外翻译来分析大量的系统设计的疏水片段，我们提出了一个定量分析的位置依赖性的贡献的所有20个氨基酸的膜插入效率，以及跨膜段长度和侧翼氨基酸的影响。转座子介导的跨膜螺旋组装的新图像是简单的，其中关键序列特征反映了脂质双层的物理性质。
Transmembrane alpha-helices in integral membrane proteins are recognized co-translationally and inserted into the membrane of the endoplasmic reticulum by the Sec61 translocon. A full quantitative description of this phenomenon, linking amino acid sequence to membrane insertion efficiency, is still lacking. Here, using in vitro translation of a model protein in the presence of dog pancreas rough microsomes to analyse a large number of systematically designed hydrophobic segments, we present a quantitative analysis of the position- dependent contribution of all 20 amino acids to membrane insertion efficiency, as well as of the effects of transmembrane segment length and flanking amino acids. The emerging picture of translocon- mediated transmembrane helix assembly is simple, with the critical sequence characteristics mirroring the physical properties of the lipid bilayer.