A conserved HEAT domain within elF4G directs assembly of the translation initiation machinery
A conserved HEAT domain within elF4G directs assembly of the translation initiation machinery
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DOI：
10.1016/s1097-2765(01)00167-8
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发表时间：
2001-01-01
期刊：
影响因子：
16
通讯作者：
Burley, SK
中科院分区：
文献类型：
--
作者：
Marcotrigiano, J;Lomakin, IB;Burley, SK
人类真核起始因子（eIF） 4GII中间部分的x射线结构在2.4埃分辨率下被确定，揭示了一个由十个α螺旋组成的新月形结构域，排列为五个HEAT重复序列。与atp依赖的RNA解旋酶eIF4A一起，该HEAT结构域足以与小核糖核酸内核糖体进入位点（IRES）形成48S核糖体复合物。基于结构的位点定向诱变用于鉴定翻译起始机制的这一重要组成部分表面的两个相邻特征，分别结合eIF4A和小核糖核酸IRES。结构和生化结果提供了对帽依赖和帽独立翻译起始的机制见解。
The X-ray structure of the phylogenetically conserved middle portion of human eukaryotic initiation factor (eIF) 4GII has been determined at 2.4 Angstrom resolution, revealing a crescent-shaped domain consisting of ten alpha helices arranged as five HEAT repeats. Together with the ATP-dependent RNA helicase eIF4A, this HEAT domain suffices for 48S ribosomal complex formation with a picornaviral RNA internal ribosome entry site (IRES). Structure-based site-directed mutagenesis was used to identify two adjacent features on the surface of this essential component of the translation initiation machinery that, respectively, bind eIF4A and a picornaviral IRES. The structural and biochemical results provide mechanistic insights into both cap-dependent and cap-independent translation initiation.