title: Identification of two distinct hybrid state intermediates on the ribosome.
abstract: High spatial and time resolution single-molecule fluorescence resonance energy transfer measurements have been used to probe the structural and kinetic parameters of transfer RNA (tRNA) movements within the aminoacyl (A) and peptidyl (P) sites of the ribosome. Our investigation of tRNA motions, quantified on wild-type, mutant, and L1-depleted ribosome complexes, reveals a dynamic exchange between three metastable tRNA configurations, one of which is a previously unidentified hybrid state in which only deacylated-tRNA adopts its hybrid (P/E) configuration. This new dynamic information suggests a framework in which the formation of intermediate states in the translocation process is achieved through global conformational rearrangements of the ribosome particle.
authors.affiliation: Department of Physiology and Biophysics, Weill Medical College of Cornell University, 1300 York Avenue, New York, NY 10021, USA.
authors.forename: James B
authors.initials: JB
authors.lastname: Munro
authors.forename: Roger B
authors.initials: RB
authors.lastname: Altman
authors.forename: Nathan
authors.initials: N
authors.lastname: O'Connor
authors.forename: Scott C
authors.initials: SC
authors.lastname: Blanchard
mesh_terms: D000215:Acylation / Q000187:drug effects; D004926:Escherichia coli / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D017353:Gene Deletion; D007700:Kinetics; D009154:Mutation / Q000235:genetics; D009690:Nucleic Acid Conformation / Q000187:drug effects; D010455:Peptides / Q000378:metabolism; D011691:Puromycin / Q000494:pharmacology; D020871:RNA Stability / Q000187:drug effects; D034443:RNA Transport; D012335:RNA, Ribosomal / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl / Q000737:chemistry / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism*
chemical_list: D010455:Peptides; D012335:RNA, Ribosomal; D012346:RNA, Transfer, Amino Acyl; D012269:Ribosomal Proteins; C028546:ribosomal protein L1; C019037:tRNA, peptidyl-; D011691:Puromycin