Conformational Changes of Elongation Factor G on the Ribosome during tRNA Translocation.Lin, J., Gagnon, M.G., Bulkley, D., Steitz, T.A.
(2015) Cell 160: 219-227
- PubMed: 25594181
- DOI: 10.1016/j.cell.2014.11.049
- Primary Citation of Related Structures:  4WPO, 4WQF, 4WQU
- PubMed Abstract:
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 dur ...
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.
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520-8114, USA.