title: Structural characterization of mRNA-tRNA translocation intermediates.
abstract: Cryo-EM analysis of a wild-type Escherichia coli pretranslocational sample has revealed the presence of previously unseen intermediate substates of the bacterial ribosome during the first phase of translocation, characterized by intermediate intersubunit rotations, L1 stalk positions, and tRNA configurations. Furthermore, we describe the domain rearrangements in quantitative terms, which has allowed us to characterize the processivity and coordination of the conformational reorganization of the ribosome, along with the associated changes in tRNA ribosome-binding configuration. The results are consistent with the view of the ribosome as a molecular machine employing Brownian motion to reach a functionally productive state via a series of substates with incremental changes in conformation.
authors.affiliation: Structural Biology Unit, CIC-bioGUNE, Bizkaia Technology Park, Derio 48160, Basque Country, Spain.
authors.forename: Xabier
authors.initials: X
authors.lastname: Agirrezabala
authors.forename: Hstau Y
authors.initials: HY
authors.lastname: Liao
authors.forename: Eduard
authors.initials: E
authors.lastname: Schreiner
authors.forename: Jie
authors.initials: J
authors.lastname: Fu
authors.forename: Rodrigo F
authors.initials: RF
authors.lastname: Ortiz-Meoz
authors.forename: Klaus
authors.initials: K
authors.lastname: Schulten
authors.forename: Rachel
authors.initials: R
authors.lastname: Green
authors.forename: Joachim
authors.initials: J
authors.lastname: Frank
mesh_terms: D001665:Binding Sites; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D046911:Macromolecular Substances / Q000737:chemistry / Q000648:ultrastructure; D008958:Models, Molecular; D008968:Molecular Conformation; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D012343:RNA, Transfer / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D012270:Ribosomes / Q000378:metabolism* / Q000648:ultrastructure; D013816:Thermodynamics
chemical_list: D046911:Macromolecular Substances; D012333:RNA, Messenger; D012343:RNA, Transfer