The Lateral Gate of SecYEG Opens during Protein Translocation
The Lateral Gate of SecYEG Opens during Protein Translocation
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DOI：
10.1074/jbc.m901855200
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发表时间：
2009-06-05
影响因子：
4.8
通讯作者：
Driessen, Arnold J. M.
中科院分区：
文献类型：
--
作者：
du Plessis, David J. F.;Berrelkamp, Greetje;Driessen, Arnold J. M.
大肠杆菌的SecYEG易位子介导前蛋白跨细胞质膜的易位。在这里，我们已经研究了在易位的建议的translocon的侧门的作用。双半胱氨酸交联方法允许在横向门的跨膜区段2b和7的相邻氨酰基位置之间引入各种长度的交联剂臂。氧化和短间隔连接器，固定在关闭状态的门废除前蛋白易位，而长间隔连接器支持易位。交联数据进一步表明SecYEG侧向门打开和SecA ATP酶的激活是偶联过程。因此，侧向门开放是SecA依赖的蛋白质转位过程中的关键步骤。
The SecYEG translocon of Escherichia coli mediates the translocation of preproteins across the cytoplasmic membrane. Here, we have examined the role of the proposed lateral gate of the translocon in translocation. A dual cysteine cross-linking approach allowed the introduction of cross-linker arms of various lengths between adjoining aminoacyl positions of transmembrane segments 2b and 7 of the lateral gate. Oxidation and short spacer linkers that fix the gate in the closed state abolished preprotein translocation, whereas long spacer linkers support translocation. The cross-linking data further suggests that SecYEG lateral gate opening and activation of the SecA ATPase are coupled processes. It is concluded that lateral gate opening is a critical step during SecA-dependent protein translocation.