An essential amino acid residue in the protein translocation channel revealed by targeted random mutagenesis of SecY
An essential amino acid residue in the protein translocation channel revealed by targeted random mutagenesis of SecY
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DOI：
10.1073/pnas.081617398
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发表时间：
2001-04-24
影响因子：
11.1
通讯作者：
Ito, K
中科院分区：
文献类型：
--
作者：
Mori, H;Ito, K
膜蛋白的SecY/Sec61 α家族是假定的蛋白质易位通道的中心亚基。我们将随机突变引入大肠杆菌SecY细胞质结构域5内的一个片段，该片段先前被证明对seca依赖性易位活性很重要。突变可分为保留功能的突变和因功能丧失而获得显性干扰能力的突变。这些分析表明，Arg-357、Pro-358、Gly-359和Thr-362具有重要的功能；Arg-357在几乎所有生物中都有保存，被认为是不可缺少的残基。
The SecY/Sec61 alpha family of membrane proteins are the central subunits of the putative protein translocation channel. We introduced random mutations into a segment of Escherichia coli SecY within its cytoplasmic domain 5, which was shown previously to be important for the SecA-dependent translocation activity. Mutations were classified into those retaining function and those gaining a dominant-interfering ability caused by a loss of function. These analyses showed that Arg-357, Pro-358, Gly-359, and Thr-362 are functionally important; Arg-357, conserved in almost all organisms, was identified as an indispensable residue.