Domain movements of elongation factor eEF2 and the eukaryotic 80S ribosome facilitate tRNA translocation
Domain movements of elongation factor eEF2 and the eukaryotic 80S ribosome facilitate tRNA translocation
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DOI：
10.1038/sj.emboj.7600102
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发表时间：
2004-03-10
期刊：
影响因子：
11.4
通讯作者：
Frank, J
中科院分区：
文献类型：
--
作者：
Spahn, CMT;Gomez-Lorenzo, MG;Frank, J
酵母80S的11.7埃分辨率低温电镜图。抗生素sordarin存在下的eEF2复合体从分子角度进行了解释，揭示了eEF2和80S核糖体内部的大构象变化，包括功能重要的核糖体亚基间桥的重排。Sordarin定位eEF2的结构域III，使其能够与25S rRNA的sarcin-ricin环和蛋白rpS23 （S12p）相互作用。这种特殊的构象解释了sordarin的抑制作用，并表明eEF2以与GTPase激活状态相似的构象停滞在80S核糖体上。棘轮样亚基重排（RSR）发生在80年代eef2。与大肠杆菌70S核糖体不同，sordarin复合体也存在于空的80S核糖体中。提出了一个模型，根据该模型，RSR是在易位反应中移动trna的机制的一部分。
An 11.7-Angstrom-resolution cryo-EM map of the yeast 80S.eEF2 complex in the presence of the antibiotic sordarin was interpreted in molecular terms, revealing large conformational changes within eEF2 and the 80S ribosome, including a rearrangement of the functionally important ribosomal intersubunit bridges. Sordarin positions domain III of eEF2 so that it can interact with the sarcin-ricin loop of 25S rRNA and protein rpS23 (S12p). This particular conformation explains the inhibitory action of sordarin and suggests that eEF2 is stalled on the 80S ribosome in a conformation that has similarities with the GTPase activation state. A ratchet-like subunit rearrangement (RSR) occurs in the 80S.eEF2.sordarin complex that, in contrast to Escherichia coli 70S ribosomes, is also present in vacant 80S ribosomes. A model is suggested, according to which the RSR is part of a mechanism for moving the tRNAs during the translocation reaction.