The E-coli signal recognition particle is required for the insertion of a subset of inner membrane proteins
The E-coli signal recognition particle is required for the insertion of a subset of inner membrane proteins
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DOI：
10.1016/s0092-8674(00)81839-5
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发表时间：
1997-01-24
期刊：
影响因子：
64.5
通讯作者：
Bernstein, HD
中科院分区：
文献类型：
--
作者：
Ulbrandt, ND;Newitt, JA;Bernstein, HD
信号识别颗粒(SRP)及其受体在大肠杆菌中的同源物对细胞的存活是必不可少的，但它们在蛋白质输出中的作用尚不清楚。为了阐明它们的功能，我们设计了一个全基因组屏幕来识别编码SRP底物的基因。抑制SRP途径可显著阻断几种可能为SRP底物的多角体内膜蛋白(IMP)的膜插入，但对其他IMP的插入影响较小，对前蛋白转位无明显影响。我们的结果表明，虽然大多数大肠杆菌前蛋白和一些IMP可以有效地利用SRP非依赖的靶向途径，但IMP子集的结构特征需要保守的基于SRP的靶向机制。
E. coli homologs of the signal recognition particle (SRP) and its receptor are essential for viability, but their role in protein export is unclear. To elucidate their function, we devised a genome-wide screen to identify genes that encode SRP substrates. Inhibition of the SRP pathway sharply blocked the membrane insertion of several polytopic inner membrane proteins (IMPs) that were predicted to be SRP substrates, but had a smaller effect on the insertion of other IMPs and no significant effect on preprotein translocation. Our results suggest that whereas most E. coli preproteins and some IMPs can utilize SRP-independent targeting pathways effectively, the structural features of a subset of IMPs have required the conservation of an SRP-based targeting machinery.