title: Thiostrepton inhibition of tRNA delivery to the ribosome.
abstract: Ribosome-stimulated hydrolysis of guanosine-5'-triphosphate (GTP) by guanosine triphosphatase (GTPase) translation factors drives protein synthesis by the ribosome. Allosteric coupling of GTP hydrolysis by elongation factor Tu (EF-Tu) at the ribosomal GTPase center to messenger RNA (mRNA) codon:aminoacyl-transfer RNA (aa-tRNA) anticodon recognition at the ribosomal decoding site is essential for accurate and rapid aa-tRNA selection. Here we use single-molecule methods to investigate the mechanism of action of the antibiotic thiostrepton and show that the GTPase center of the ribosome has at least two discrete functions during aa-tRNA selection: binding of EF-Tu(GTP) and stimulation of GTP hydrolysis by the factor. We separate these two functions of the GTPase center and assign each to distinct, conserved structural regions of the ribosome. The data provide a specific model for the coupling between the decoding site and the GTPase center during aa-tRNA selection as well as a general mechanistic model for ribosome-stimulated GTP hydrolysis by GTPase translation factors.
authors.affiliation: Department of Structural Biology, Stanford University School of Medicine, Stanford, California 94305-5126, USA.
authors.forename: Ruben L
authors.initials: RL
authors.lastname: Gonzalez
authors.forename: Steven
authors.initials: S
authors.lastname: Chu
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Puglisi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D020558:GTP Phosphohydrolases / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D008958:Models, Molecular; D008967:Molecular Biology; D009690:Nucleic Acid Conformation; D010444:Peptide Elongation Factor Tu / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics*; D012343:RNA, Transfer / Q000187:drug effects / Q000235:genetics*; D012270:Ribosomes / Q000187:drug effects / Q000502:physiology*; D013050:Spectrometry, Fluorescence; D013883:Thiostrepton / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D012333:RNA, Messenger; D006160:Guanosine Triphosphate; D012343:RNA, Transfer; D020558:GTP Phosphohydrolases; D010444:Peptide Elongation Factor Tu; D013883:Thiostrepton