4v9p

Publication Abstract from PubMed

Protein synthesis by the ribosome requires the translocation of transfer RNAs and messenger RNA by one codon after each peptide bond is formed, a reaction that requires ribosomal subunit rotation and is catalyzed by the guanosine triphosphatase (GTPase) elongation factor G (EF-G). We determined 3 angstrom resolution x-ray crystal structures of EF-G complexed with a nonhydrolyzable guanosine 5'-triphosphate (GTP) analog and bound to the Escherichia coli ribosome in different states of ribosomal subunit rotation. The structures reveal that EF-G binding to the ribosome stabilizes switch regions in the GTPase active site, resulting in a compact EF-G conformation that favors an intermediate state of ribosomal subunit rotation. These structures suggest that EF-G controls the translocation reaction by cycles of conformational rigidity and relaxation before and after GTP hydrolysis.

Control of ribosomal subunit rotation by elongation factor G.,Pulk A, Cate JH Science. 2013 Jun 28;340(6140):1235970. doi: 10.1126/science.1235970. PMID:23812721^[1]

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