4v9p is a 217 chain structure with sequence from  and Escherichia coli. This structure supersedes the now removed PDB entries and 4kjc. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Pulk A, Cate JH. Control of ribosomal subunit rotation by elongation factor G. Science. 2013 Jun 28;340(6140):1235970. doi: 10.1126/science.1235970. PMID:23812721 doi:10.1126/science.1235970