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Publication Abstract from PubMed

In an attempt to understand ribosome-induced GTP hydrolysis on eEF2, we determined a 12.6-A 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 transition-state 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.

Visualization of the eEF2-80S ribosome transition-state complex by cryo-electron microscopy.,Sengupta J, Nilsson J, Gursky R, Kjeldgaard M, Nissen P, Frank J J Mol Biol. 2008 Sep 26;382(1):179-87. Epub 2008 Jul 11. PMID:18644383^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.