title: Large-scale movement of elongation factor G and extensive conformational change of the ribosome during translocation.
abstract: Elongation factor (EF) G promotes tRNA translocation on the ribosome. We present three-dimensional reconstructions, obtained by cryo-electron microscopy, of EF-G-ribosome complexes before and after translocation. In the pretranslocation state, domain 1 of EF-G interacts with the L7/12 stalk on the 50S subunit, while domain 4 contacts the shoulder of the 30S subunit in the region where protein S4 is located. During translocation, EF-G experiences an extensive reorientation, such that, after translocation, domain 4 reaches into the decoding center. The factor assumes different conformations before and after translocation. The structure of the ribosome is changed substantially in the pretranslocation state, in particular at the head-to-body junction in the 30S subunit, suggesting a possible mechanism of translocation.
authors.affiliation: Imperial College of Science Medicine and Technology, Department of Biochemistry, London, United Kingdom.
authors.forename: H
authors.initials: H
authors.lastname: Stark
authors.forename: M V
authors.initials: MV
authors.lastname: Rodnina
authors.forename: H J
authors.initials: HJ
authors.lastname: Wieden
authors.forename: M
authors.initials: M
authors.lastname: van Heel
authors.forename: W
authors.initials: W
authors.lastname: Wintermeyer
mesh_terms: D005672:Fusidic Acid / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted; D008958:Models, Molecular; D008961:Models, Structural; D008968:Molecular Conformation; D009068:Movement; D010441:Peptide Chain Elongation, Translational / Q000187:drug effects; D020653:Peptide Elongation Factor G / Q000648:ultrastructure*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012343:RNA, Transfer / Q000648:ultrastructure*; D012358:RNA, Transfer, Met / Q000648:ultrastructure; D012360:RNA, Transfer, Phe / Q000648:ultrastructure; D012270:Ribosomes / Q000648:ultrastructure*
chemical_list: D020653:Peptide Elongation Factor G; D011500:Protein Synthesis Inhibitors; D012358:RNA, Transfer, Met; D012360:RNA, Transfer, Phe; C024988:tRNA, formylmethionine-; D005672:Fusidic Acid; D012343:RNA, Transfer