Structure of eEF3 and the mechanism of transfer RNA release from the E-site
Structure of eEF3 and the mechanism of transfer RNA release from the E-site
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DOI：
10.1038/nature05126
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发表时间：
2006-10-12
期刊：
影响因子：
64.8
通讯作者：
Beckmann, Roland
中科院分区：
文献类型：
--
作者：
Andersen, Christian B. F.;Becker, Thomas;Beckmann, Roland
伸长因子EEF3是一种ATPase，除了两个规范因子EEF1A和EEF2外，它在真菌的翻译周期中起着重要的功能。 EEF3是氨基酰基-TRNA-EEF1A-GTP三元络合物与核糖体A位点结合所必需的，并已建议促进从E位置清除Deacyl-TRNA。在这里，我们介绍了酿酒酵母EEF3的晶体结构，表明它由氨基末端热重复结构域组成，然后是一个四螺旋束和两个ABC型ATPase域，并在ABC2中插入了染色体。此外，我们介绍了EEF3与酵母转换后80S核糖体复合物的ATP结合形式的冷冻电子显微镜结构。 EEF3在核糖体E位置附近使用一个全新的因子结合位点，其中染色体可能会以开放的构型稳定核糖体L1茎，从而允许tRNA释放。
Elongation factor eEF3 is an ATPase that, in addition to the two canonical factors eEF1A and eEF2, serves an essential function in the translation cycle of fungi. eEF3 is required for the binding of the aminoacyl-tRNA-eEF1A-GTP ternary complex to the ribosomal A-site and has been suggested to facilitate the clearance of deacyl-tRNA from the E-site. Here we present the crystal structure of Saccharomyces cerevisiae eEF3, showing that it consists of an amino-terminal HEAT repeat domain, followed by a four-helix bundle and two ABC-type ATPase domains, with a chromodomain inserted in ABC2. Moreover, we present the cryo-electron microscopy structure of the ATP-bound form of eEF3 in complex with the post-translocational-state 80S ribosome from yeast. eEF3 uses an entirely new factor binding site near the ribosomal E-site, with the chromodomain likely to stabilize the ribosomal L1 stalk in an open conformation, thus allowing tRNA release.