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-Structure paper
タイトル | Activation of GTP hydrolysis in mRNA-tRNA translocation by elongation factor G. |
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ジャーナル・号・ページ | Sci Adv, Vol. 1, Issue 4, Year 2015 |
掲載日 | 2015年5月1日 |
著者 | Wen Li / Zheng Liu / Ravi Kiran Koripella / Robert Langlois / Suparna Sanyal / Joachim Frank / |
PubMed 要旨 | During protein synthesis, elongation of the polypeptide chain by each amino acid is followed by a translocation step in which mRNA and transfer RNA (tRNA) are advanced by one codon. This crucial step ...During protein synthesis, elongation of the polypeptide chain by each amino acid is followed by a translocation step in which mRNA and transfer RNA (tRNA) are advanced by one codon. This crucial step is catalyzed by elongation factor G (EF-G), a guanosine triphosphatase (GTPase), and accompanied by a rotation between the two ribosomal subunits. A mutant of EF-G, H91A, renders the factor impaired in guanosine triphosphate (GTP) hydrolysis and thereby stabilizes it on the ribosome. We use cryogenic electron microscopy (cryo-EM) at near-atomic resolution to investigate two complexes formed by EF-G H91A in its GTP state with the ribosome, distinguished by the presence or absence of the intersubunit rotation. Comparison of these two structures argues in favor of a direct role of the conserved histidine in the switch II loop of EF-G in GTPase activation, and explains why GTP hydrolysis cannot proceed with EF-G bound to the unrotated form of the ribosome. |
リンク | Sci Adv / PubMed:26229983 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.6 Å |
構造データ | |
化合物 | ChemComp-GTP: |
由来 |
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キーワード | RIBOSOME / 70S ribosome / elongation factor G / EF-G |