Alignment of conduits for the nascent polypeptide chain in the Ribosome-Sec61 complex
Alignment of conduits for the nascent polypeptide chain in the Ribosome-Sec61 complex
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DOI：
10.1126/science.278.5346.2123
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发表时间：
1997-12-19
期刊：
影响因子：
56.9
通讯作者：
Frank, J
中科院分区：
文献类型：
--
作者：
Beckmann, R;Bubeck, D;Frank, J
Sec 61三聚体复合物的寡聚体被认为形成蛋白质传导通道，用于蛋白质转运穿过内质网。纯化的酵母Sec 61复合物以可饱和的方式作为寡聚体结合到单体酵母核糖体。核糖体-Sec 61复合物的冷冻电子显微镜和三维重建显示，Sec 61寡聚体通过单一连接附着于核糖体大亚基。此外，在Sec 61寡聚体中的漏斗形孔与穿过核糖体大亚基的隧道的出口对齐，强烈表明这两种结构在蛋白质跨内质网膜的易位中一起起作用。
An oligomer of the Sec61 trimeric complex is thought to form the protein-conducting channel for protein transport across the endoplasmic reticulum. A purified yeast Sec61 complex bound to monomeric yeast ribosomes as an oligomer in a saturable fashion. Cryo-electron microscopy of the ribosome-Sec61 complex and a three-dimensional reconstruction showed that the Sec61 oligomer is attached to the large ribosomal subunit by a single connection. Moreover, a funnel-shaped pore in the Sec61 oligomer aligned with the exit of a tunnel traversing the large ribosomal subunit, strongly suggesting that both structures function together in the translocation of proteins across the endoplasmic reticulum membrane.