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-Structure paper
Title | Activation of GTP hydrolysis in mRNA-tRNA translocation by elongation factor G. |
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Journal, issue, pages | Sci Adv, Vol. 1, Issue 4, Year 2015 |
Publish date | May 1, 2015 |
Authors | Wen Li / Zheng Liu / Ravi Kiran Koripella / Robert Langlois / Suparna Sanyal / Joachim Frank / |
PubMed Abstract | 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. |
External links | Sci Adv / PubMed:26229983 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.6 Å |
Structure data | |
Chemicals | ChemComp-GTP: |
Source |
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Keywords | RIBOSOME / 70S ribosome / elongation factor G / EF-G |