title: Structural investigation of Phe-tRNAPhe from E.coli bound to the ribosomal A-site.
abstract: Kethoxal modification of guanosines within Phe-tRNAPhe from E. coli was studied for tRNA in the free state and specifically bound to the ribosomal A-site. Complex formation with the ribosome results in a protection from chemical modification of two distant sites in the tRNA molecule. The guanosines affected are G-18 and G-19, located in the D-loop, and G-34 in the anticodon loop. Modification of Phe-tRNAPhe in the absence of ribosomes leads to a destabilisation of the tRNA structure. Our data are consistent with the conclusion that modification of G-34 at the anticodon loop triggers a conformational instability in distant parts of the tRNA molecule.
mesh_terms: D000447:Aldehydes / Q000494:pharmacology; D000998:Antiviral Agents / Q000494:pharmacology; D001483:Base Sequence; D002074:Butanones; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D012346:RNA, Transfer, Amino Acyl / Q000235:genetics*; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000447:Aldehydes; D000998:Antiviral Agents; D002074:Butanones; D012346:RNA, Transfer, Amino Acyl; C005135:kethoxal