Crepin Thibaut, Shalak Vyacheslav F, Yaremchuk Anna D, Vlasenko Dmytro O, McCarthy Andrew, Negrutskii Boris S, Tukalo Michail A, El'skaya Anna V
University of Grenoble Alpes, UVHCI, F-38000 Grenoble, France CNRS, UVHCI, F-38000 Grenoble, France Unit for Virus Host-Cell Interactions, University of Grenoble Alpes-EMBL-CNRS, 71 avenue des Martyrs, 38042 France.
State Key laboratory of Molecular and Cellular Biology, Institute of Molecular Biology and Genetics, 150 Zabolotnogo str., Kiev 03680, Ukraine.
Nucleic Acids Res. 2014 Nov 10;42(20):12939-48. doi: 10.1093/nar/gku974. Epub 2014 Oct 17.
Eukaryotic elongation factor eEF1A transits between the GTP- and GDP-bound conformations during the ribosomal polypeptide chain elongation. eEF1AGTP establishes a complex with the aminoacyl-tRNA in the A site of the 80S ribosome. Correct codon-anticodon recognition triggers GTP hydrolysis, with subsequent dissociation of eEF1AGDP from the ribosome. The structures of both the 'GTP'- and 'GDP'-bound conformations of eEF1A are unknown. Thus, the eEF1A-related ribosomal mechanisms were anticipated only by analogy with the bacterial homolog EF-Tu. Here, we report the first crystal structure of the mammalian eEF1A2GDP complex which indicates major differences in the organization of the nucleotide-binding domain and intramolecular movements of eEF1A compared to EF-Tu. Our results explain the nucleotide exchange mechanism in the mammalian eEF1A and suggest that the first step of eEF1AGDP dissociation from the 80S ribosome is the rotation of the nucleotide-binding domain observed after GTP hydrolysis.
真核生物延伸因子eEF1A在核糖体多肽链延伸过程中在结合GTP和结合GDP的构象之间转换。eEF1A·GTP在80S核糖体的A位点与氨酰tRNA形成复合物。正确的密码子-反密码子识别引发GTP水解，随后eEF1A·GDP从核糖体上解离。eEF1A结合GTP和结合GDP构象的结构均未知。因此，与eEF1A相关的核糖体机制仅通过与细菌同源物EF-Tu类比来推测。在此，我们报道了哺乳动物eEF1A2·GDP复合物的首个晶体结构，该结构表明与EF-Tu相比，eEF1A的核苷酸结合结构域组织和分子内运动存在主要差异。我们的结果解释了哺乳动物eEF1A中的核苷酸交换机制，并表明eEF1A·GDP从80S核糖体解离的第一步是GTP水解后观察到的核苷酸结合结构域的旋转。
