title: Translocation as continuous movement through the ribosome.
abstract: In each round of translation elongation, tRNAs and mRNA move within the ribosome by one codon at a time. tRNA-mRNA translocation is promoted by elongation factor G (EF-G) at the cost of GTP hydrolysis. The key questions for understanding translocation are how and when the tRNAs move and how EF-G coordinates motions of the ribosomal subunits with tRNA movement. Here we present 2 recent papers which describe the choreography of movements over the whole trajectory of translocation. We present the view that EF-G accelerates translocation by promoting the steps that lead to GTPase-dependent ribosome unlocking. EF-G facilitates the formation of the rotated state of the ribosome and uncouples the backward motions of the ribosomal subunits, forming an open conformation in which the tRNAs can rapidly move. Ribosome dynamics are important not only in translocation, but also in recoding events, such as frameshifting and bypassing, and mediate sensitivity to antibiotics.
authors: a Max Planck Institute for Biophysical Chemistry , Department of Physical Biochemistry , Göttingen , Germany.
authors: Riccardo
authors: R
authors: Belardinelli
authors: a Max Planck Institute for Biophysical Chemistry , Department of Physical Biochemistry , Göttingen , Germany.
authors: Heena
authors: H
authors: Sharma
authors: a Max Planck Institute for Biophysical Chemistry , Department of Physical Biochemistry , Göttingen , Germany.
authors: Frank
authors: F
authors: Peske
authors: a Max Planck Institute for Biophysical Chemistry , Department of Physical Biochemistry , Göttingen , Germany.
authors: Wolfgang
authors: W
authors: Wintermeyer
authors: a Max Planck Institute for Biophysical Chemistry , Department of Physical Biochemistry , Göttingen , Germany.
authors: Marina V
authors: MV
authors: Rodnina
mesh_terms: D006160:Guanosine Triphosphate / Q000737:chemistry; D006868:Hydrolysis; D008958:Models, Molecular; D020653:Peptide Elongation Factor G / Q000737:chemistry / Q000378:metabolism*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism*; D012343:RNA, Transfer / Q000737:chemistry / Q000378:metabolism*; D012270:Ribosomes / Q000737:chemistry / Q000378:metabolism*
chemical_list: D020653:Peptide Elongation Factor G; D012333:RNA, Messenger; D006160:Guanosine Triphosphate; D012343:RNA, Transfer
keywords: EF-G; mRNA; molecular machines; protein synthesis; ribosome; tRNA; translation; translation elongation; translocation