title: Dinucleotide codon-anticodon interaction as a minimum requirement for ribosomal aa-tRNA binding: stabilisation by viomycin of aa-tRNA in the A site.
abstract: The requirements for the decoding process at the ribosomal A site have been investigated in the presence of viomycin. For these studies natural mRNA was replaced either by the synthetic oligonucleotide A-U-G(-U)n, with 0 less than or equal to n less than or equal to 4, or by a physical mixture of the oligonucleotides A-U-G and various oligo(U) sequences. Thus the effect of the "removal" of selected covalent bonds from the sequence A-U-G(U)n could be studied. When the ribosomal P site contains tRNAMetf, then normally the full hexanucleotide "messenger" A-U-G-U-U-U is needed for the EF-Tu-mediated binding of Phe-tRNA into the A site. However in presence of viomycin the pentanucleotide A-U-G-U-U suffices for this. It is also possible in the presence of viomycin to replace A-U-G-U and U-U. In all the above systems the binding of Phe-tRNA required the presence of EF-Tu and GTP. The results suggest that viomycin reinforces interactions between aa-tRNA and the A site after the codon-anticodon recognition step.
mesh_terms: D000926:Anticodon / Q000378:metabolism*; D001665:Binding Sites; D003062:Codon / Q000378:metabolism*; D004151:Dipeptides / Q000096:biosynthesis; D004926:Escherichia coli / Q000378:metabolism; D009843:Oligoribonucleotides / Q000378:metabolism; D012329:RNA, Bacterial / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012343:RNA, Transfer / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D012270:Ribosomes / Q000187:drug effects / Q000378:metabolism*; D014756:Viomycin / Q000494:pharmacology*
chemical_list: D000926:Anticodon; D003062:Codon; D004151:Dipeptides; D009843:Oligoribonucleotides; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012346:RNA, Transfer, Amino Acyl; D012343:RNA, Transfer; D014756:Viomycin