Recognition of a signal peptide by the signal recognition particle.
Recognition of a signal peptide by the signal recognition particle.
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作者：
在所有活细胞中，将蛋白质靶向到合适的亚细胞区室是一个至关重要的过程。分泌蛋白和膜蛋白通常含有n端信号肽，当新生多肽链从核糖体中出现时，信号识别粒子（SRP）识别该信号肽。然后，通过其与srp受体的gtp依赖性相互作用，将srp -核糖体新生链复合物靶向真核生物内质网膜或细菌质膜上的蛋白质传导通道。SRP的一个普遍保守的成分，SRP54或其细菌同源物，54同源物（Ffh），结合具有高度分化序列的信号肽，这些信号肽可分为带正电的n区，通常含有8-20个疏水残基的h区和极性c区。目前还没有报道表明SRP54结合任何信号序列的结构。我们在solfataricus Sulfolobus SRP54和一个通过柔性连接体连接的信号肽之间制备了一个融合蛋白。该融合蛋白通过SRP54与不同链上的信号肽片段相互作用，在溶液中寡聚，具有功能性，能够结合SRP RNA和SRP受体FtsY。在这里，我们展示了SRP54-信号肽复合物在3.5 Å分辨率下的晶体结构，揭示了SRP54如何识别信号序列。
Targeting of proteins to appropriate sub-cellular compartments is a crucial process in all living cells. Secretory and membrane proteins usually contain an N-terminal signal peptide, which is recognised by the signal recognition particle (SRP) when nascent polypeptide chains emerge from the ribosome. The SRP-ribosome nascent chain complex is then targeted through its GTP-dependent interaction with SRP-receptor to the protein-conducting channel on endoplasmic reticulum membrane in eukaryotes or plasma membrane in bacteria. A universally conserved component of SRP, SRP54 or its bacterial homolog, fifty-four homolog (Ffh), binds the signal peptides which have a highly divergent sequence divisible into a positively charged n-region, an h-region commonly containing 8-20 hydrophobic residues and a polar c-region. No structure has been reported that exemplified SRP54 binding of any signal sequence. We have produced a fusion protein between Sulfolobus solfataricus SRP54 and a signal peptide connected via a flexible linker. This fusion protein oligomerises in solution, through interaction between the SRP54 and signal peptide moieties belonging to different chains, and it is functional, able to bind SRP RNA and SRP-receptor FtsY. Here we present the crystal structure at 3.5 Å resolution of an SRP54-signal peptide complex in the dimer, which reveals how a signal sequence is recognised by SRP54.
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DOI：
10.1107/s0907444905036693
发表时间：
2006-01-01
影响因子：
2.2
作者：
Evans, P
通讯作者：
Evans, P
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
14.8
作者：
Hernandez, Helena;Robinson, Carol V.
通讯作者：
Robinson, Carol V.
DOI：
10.1073/pnas.2436132100
发表时间：
2003-12-09
影响因子：
11.1
作者：
Rosendal, KR;Wild, K;Sinning, L
通讯作者：
Sinning, L
DOI：
10.1038/nsb843
发表时间：
2002-10-01
期刊：
NATURE STRUCTURAL BIOLOGY
影响因子：
--
作者：
Kuglstatter, A;Oubridge, C;Nagai, K
通讯作者：
Nagai, K