Solution structure and RNA interactions of the RNA recognition motif from eukaryotic translation initiation factor 4B
Solution structure and RNA interactions of the RNA recognition motif from eukaryotic translation initiation factor 4B
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DOI：
10.1021/bi034506g
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发表时间：
2003-08-05
期刊：
影响因子：
2.9
通讯作者：
Curry, S
中科院分区：
文献类型：
--
作者：
Fleming, K;Ghuman, J;Curry, S
真核细胞起始因子4B(EIF4B)是一种具有多种活性的多结构域蛋白，在翻译起始过程中主要促进信使RNA与40S核糖体亚基的结合。我们报道了eIF4B RNA识别基序(RRM)结构域的溶液结构。它采用经典的RRM折叠，具有BetaphabetaAlphabeta拓扑。与其他RRM结构最显著的区别是环3的配置，它连接Beta(2)和beta(3)链，并与RNA识别有关。这个环向下对着RRM的身体折叠，并在毫秒到微秒的时间尺度上显示出受限的运动。虽然它在RNA结合面上形成了一个大的基本补丁，但它并没有像在其他RRM结构中观察到的那样从结构域中突出出来，这可能意味着不同的RNA结合模式。就其本身而言，核心RRM结构域仅提供与RNA靶标的相对较弱的相互作用，并且似乎需要在N-末端和C-末端延伸才能高亲和力结合。
Eukaryotic initiation factor 4B (eIF4B) is a multidomain protein with a range of activities that serves primarily to promote association of messenger RNA to the 40S ribosomal subunit during translation initiation. We report here the solution structure of the eIF4B RNA recognition motif (RRM) domain. It adopts a classical RRM fold, with a betaalphabetabetaalphabeta topology. The most striking difference with other RRM structures is in the disposition of loop 3, which connects the beta(2) and beta(3) strands and is implicated in RNA recognition. This loop folds down against the body of the RRM and exhibits restricted motion on a milli-to microsecond time scale. Although it contributes to a large basic patch on the RNA binding surface, it does not protrude out from the domain as observed in other RRM structures, possibly implying a different mode of RNA binding. On its own, the core RRM domain provides only a relative weak interaction with RNA targets and appears to require extensions at the N- and C-terminus for high-affinity binding.