YidC, an assembly site for polytopic Escherichia coli membrane proteins located in immediate proximity to the SecYE translocon and lipids
YidC, an assembly site for polytopic Escherichia coli membrane proteins located in immediate proximity to the SecYE translocon and lipids
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DOI：
10.1093/embo-reports/kve154
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发表时间：
2001-08-01
期刊：
影响因子：
7.7
通讯作者：
Müller, M
中科院分区：
文献类型：
--
作者：
Beck, K;Eisner, G;Müller, M
与其线粒体同源物Oxa1 p一样，大肠杆菌的内膜蛋白YidC参与膜蛋白的整合。我们分析了多位大肠杆菌膜蛋白MtIA作为核糖体新生链复合物靶向内膜囊泡的各个插入步骤。YidC可以在蛋白质脂质界面处容纳MtIA的至少前两个跨膜区段并保留它们，即使新生链的长度将充分允许插入膜脂质中。描述了MtIA的甚至更长的插入中间体，其仍然具有与YidC结合的第一跨膜螺旋，而第三跨膜螺旋在整合期间接触SecE和YidC。我们的研究结果表明，YidC形成一个连续的整合单位与SecYE易位子和功能作为组装位点的多位膜蛋白介导的螺旋束的形成之前，他们释放到膜脂质。
Like its mitochondrial homolog Oxa1p, the inner membrane protein YidC of Escherichia coli is involved in the integration of membrane proteins. We have analyzed individual insertion steps of the polytopic E coli membrane protein MtIA targeted as ribosome-nascent chain complexes to inner membrane vesicles. YidC can accommodate at least the first two transmembrane segments of MtIA at the protein lipid interface and retain them even though the length of the nascent chain would amply allow insertion into membrane lipids. An even longer insertion intermediate of MtIA is described that still has the first transmembrane helix bound to YidC while the third contacts SecE and YidC during integration. Our findings suggest that YidC forms a contiguous integration unit with the SecYE translocon and functions as an assembly site for polytopic membrane proteins mediating the formation of helix bundles prior to their release into the membrane lipids.