title: An A to U transversion at position 1067 of 23 S rRNA from Escherichia coli impairs EF-Tu and EF-G function.
abstract: Escherichia coli ribosomes with an A to U transversion at nucleotide 1067 of their 23 S rRNA are impaired in their effective association rate constants (kcat/KM) for both EF-Tu and EF-G binding. In addition, the times that EF-G and EF-Tu spend on the ribosome during elongation are significantly increased by the A to U transversion. The U1067 mutation impairs EF-Tu function more than EF-G function. The increase in the time that EF-Tu remains bound to ribosome is caused, both by a slower rate of GTP-hydrolysis in ternary complex and by a slower EF-Tu.GDP release from the mutated ribosomes. There is, at the same time, no change in ribosomal accuracy for aminoacyl-tRNA recognition. With support from these new data we propose that nucleotide 1067 is part of the ribosomal A-site where it directly interacts with both EF-G and EF-Tu.
authors.affiliation: Institute of Molecular and Cell Biology, Department of Molecular Biology, Tartu University, Tartu, EE2400, Estonia.
authors.forename: U
authors.initials: U
authors.lastname: Saarma
authors.forename: J
authors.initials: J
authors.lastname: Remme
authors.forename: M
authors.initials: M
authors.lastname: Ehrenberg
authors.forename: N
authors.initials: N
authors.lastname: Bilgin
mesh_terms: D000225:Adenine; D004926:Escherichia coli / Q000235:genetics*; D006160:Guanosine Triphosphate / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D009154:Mutation; D010441:Peptide Chain Elongation, Translational / Q000235:genetics*; D020653:Peptide Elongation Factor G; D010444:Peptide Elongation Factor Tu / Q000378:metabolism; D010445:Peptide Elongation Factors / Q000378:metabolism*; D012338:RNA, Ribosomal, 23S / Q000235:genetics / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism; D012270:Ribosomes / Q000235:genetics / Q000378:metabolism*; D014529:Uridine
chemical_list: D020653:Peptide Elongation Factor G; D010445:Peptide Elongation Factors; D012338:RNA, Ribosomal, 23S; D012346:RNA, Transfer, Amino Acyl; C019037:tRNA, peptidyl-; D006160:Guanosine Triphosphate; D010444:Peptide Elongation Factor Tu; D000225:Adenine; D014529:Uridine