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Publication Abstract from PubMed

The universally conserved GTPase elongation factor G (EF-G) catalyzes the translocation of tRNA and mRNA on the ribosome after peptide bond formation. Despite numerous studies suggesting that EF-G undergoes extensive conformational rearrangements during translocation, high-resolution structures exist for essentially only one conformation of EF-G in complex with the ribosome. Here, we report four atomic-resolution crystal structures of EF-G bound to the ribosome programmed in the pre- and posttranslocational states and to the ribosome trapped by the antibiotic dityromycin. We observe a previously unseen conformation of EF-G in the pretranslocation complex, which is independently captured by dityromycin on the ribosome. Our structures provide insights into the conformational space that EF-G samples on the ribosome and reveal that tRNA translocation on the ribosome is facilitated by a structural transition of EF-G from a compact to an elongated conformation, which can be prevented by the antibiotic dityromycin.

Conformational Changes of Elongation Factor G on the Ribosome during tRNA Translocation.,Lin J, Gagnon MG, Bulkley D, Steitz TA Cell. 2015 Jan 15;160(1-2):219-27. doi: 10.1016/j.cell.2014.11.049. PMID:25594181^[1]

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