The signal sequence interacts with the methionine-rich domain of the 54-kD protein of signal recognition particle.
The signal sequence interacts with the methionine-rich domain of the 54-kD protein of signal recognition particle.
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DOI：
10.1083/jcb.113.2.229
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发表时间：
1991-04
期刊：
影响因子：
--
通讯作者：
Dobberstein B
中科院分区：
文献类型：
--
作者：
High S;Dobberstein B
新生催乳素前体的信号序列与信号识别颗粒（SRP 54）的54-kD蛋白相互作用。为了鉴定与信号序列相互作用的SRP 54上的结构域或位点，我们使用了光交联方法，然后使用对SRP 54的限定区域特异性的抗肽抗体进行有限的蛋白水解和免疫沉淀。我们发现先前鉴定的SRP 54的富含甲硫氨酸的RNA结合结构域（SRP 54 M结构域）也与信号序列相互作用。发现与信号序列交联的最小片段包含SRP 54 M结构域的COOH末端6-kD片段。未发现与SRP 54的GTP结合结构域（SRP 54 G结构域）的交联，SRP 54 M结构域和SRP 54 G结构域之间的蛋白水解切割并不影响信号序列与SRP 54 M结构域之间的后续相互作用。我们的研究结果表明，SRP 54的RNA结合和信号序列结合功能都是由SRP 54 M结构域执行的。
The signal sequence of nascent preprolactin interacts with the 54-kD protein of the signal recognition particle (SRP54). To identify the domain or site on SRP54 that interacts with the signal sequence we used a photocross-linking approach followed by limited proteolysis and immunoprecipitation using anti-peptide antibodies specific for defined regions of SRP54. We found that the previously identified methionine- rich RNA-binding domain of SRP54 (SRP54M domain) also interacts with the signal sequence. The smallest fragment that was found to be crosslinked to the signal sequence comprised the COOH-terminal 6-kD segment of the SRP54M domain. No cross-link to the putative GTP-binding domain of SRP54 (SRP54G domain) was found. Proteolytic cleavage between the SRP54M domain and SRP54G domain did not impair the subsequent interaction between the signal sequence and the SRP54M domain. Our results show that both the RNA binding and signal sequence binding functions of SRP54 are performed by the SRP54M domain.