Visualization of the eEF2-80S ribosome transition-state complex by cryo-electron microscopy

JOURNAL OF MOLECULAR BIOLOGY

卷:382

Article

Nilsson, Jakob¹  Gursky, Richard²  Kieldgaard, Morten¹  Nissen, Poul¹  Frank, Joachim^2,3 

[1] Univ Aarhus, Dept Mol Biol, DK-8000 Aarhus, Denmark

[2] New York State Dept Hlth, Wadsworth Ctr, Howard Hughes Med Inst, Hlth Res Inc, Albany, NY 12201 USA

[3] SUNY Albany, Dept Biomed Sci, Albany, NY 12201 USA

关键词: AlF4-;    GDP;    GTPase;    ribosome;    translocation;   

DOI  :  10.1016/j.jmb.2008.07.004

来源: Elsevier

【 摘 要 】

In an attempt to understand ribosome-induced GTP hydrolysis on eEF2, we determined a 12.6-angstrom cryo-electron microscopy reconstruction of the eEF2-bound 80S ribosome in the presence of aluminum tetrafluoride and GDP, with aluminum tetrafluoride mimicking the gamma-phosphate during hydrolysis. This is the first visualization of a structure representing a transitionstate complex on the ribosome. Tight interactions are observed between the factor's G domain and the large ribosomal subunit, as well as between domain IV and an intersubunit bridge. In contrast, some of the domains of eEF2 implicated in small subunit binding display a large degree of flexibility. Furthermore, we find support for a transition-state model conformation of the switch I region in this complex where the reoriented switch I region interacts with a conserved rRNA region of the 40S subunit formed by loops of the 18S RNA helices 8 and 14. This complex is structurally distinct from the eEF2-bound 80S ribosome complexes previously reported, and analysis of this map sheds light on the GTPase-coupled translocation mechanism. (C) 2008 Elsevier Ltd. All rights reserved.

【 授权许可】

Free