结构的单体酵母和哺乳动物Sec61.doc

Structure of Monomeric Yeast and Mammalian Sec61 Interacting Complexes with the Translating Ribosome 单体酵母和哺乳动物Sec61的结构 交互配合物与翻译核糖体 Thomas Becker, 1 Shashi Bhushan, 1 Alexander Jarasch, 1 Jean-Paul Armache, 1 Soledad Funes, 1,2 Fabrice Jossinet, 3 James Gumbart, 4 Thorsten Mielke, 5,6 Otto Berninghausen, 1 Klaus Schulten, 4 Eric Westhof, 3 Reid Gilmore, 7 Elisabet C. Mandon, 7 * Roland Beckmann1 * 托马斯贝克尔，1沙市布尚，1亚历山大雅拉施，1让保罗Armache，1索莱达富内斯，1,2法布里若西内，3詹姆斯冈巴特，4 Thorsten米尔克，5,6奥托伯宁豪森，1克劳斯舒尔滕，4埃里克Westhof，3里德吉尔摩，7伊丽莎白长芒东，7 罗兰Beckmann1 The trimeric Sec61/SecY complex is a protein-conducting channel (PCC) for secretory and membrane proteins. Although Sec complexes can form oligomers, it has been suggested that a single copy may serve as an active PCC. We determined subnanometer-resolution cryo–electron microscopy structures of eukaryotic ribosome-Sec61 complexes. In combination with biochemical data, we found that in both idle and active states, the Sec complex is not oligomeric and interacts mainly via two cytoplasmic loops with the universal ribosomal adaptor site. In the active state, the ribosomal tunnel and a central pore of the monomeric PCC were occupied by the nascent chain,contacting loop 6 of the Sec complex. This provides a structural basis for the activity of a solitary Sec complex in cotranslational protein translocation. 三聚Sec61/SecY配合物蛋白质-指挥渠道(PCC)Sec配合物一活跃PCC用被建议在和活跃状态中Sec配合物不是低聚物，交互主要通过两个细胞质核糖体循环。在活动状态中，核糖体通道和单体的 PCC被诞生中的链条占领Sec配合物的6连接。Sec配合物翻译蛋白质运输活动的结构基础。 The protein-conducting channel (PCC) of the canonical secretory pathway is formed in all cells by the Sec61/SecY complex. It engages in the post- and cotranslational translocation of secretory proteins across and the insertion of integral membrane proteins into the membrane of the endoplasmic reticulum in eukaryotes and the plasma membrane of bacteria (1, 2). 这种蛋白质导电通道的规范分泌途径是所有细胞中形成的Sec61/SecY配合物。它从事的分泌蛋白和跨越和膜蛋白的组成插入翻译易位在真核生物内质网和细菌（1，2）细胞膜。 In the cotranslational translocation mode, the ribosome with a