title: A rRNA-mRNA base pairing model for UGA-dependent termination.
abstract: A series of site-directed mutations has been constructed in E coli 16S rRNA and shown to suppress UGA-dependent translational termination. With the exception of the C726 to G base change, all were constructed in helix 34. Characterization of these mutations is reviewed here and from these data and mRNA-rRNA base pairing model for the termination event is presented. The interaction functions via antiparallel base pairing between either 1 of the 2 UCA motifs in helix 34 and the complementary UGA stop codon on the message, thus forming a quasicontinuous A-type helical structure that is further stabilized by stacking enthalpy. Finally, rRNA motifs potentially required for UAA and UAG-dependent translational termination are discussed.
authors.affiliation: MAX-Planck-Institut für Molekulare Genetik, Abt Wittmann, Berlin, Germany.
authors.forename: C D
authors.initials: CD
authors.lastname: Prescott
authors.forename: B
authors.initials: B
authors.lastname: Kleuvers
authors.forename: H U
authors.initials: HU
authors.lastname: Göringer
mesh_terms: D001483:Base Sequence; D003062:Codon / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D010443:Peptide Chain Termination, Translational; D010454:Peptide Termination Factors / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000378:metabolism*
chemical_list: D003062:Codon; D010454:Peptide Termination Factors; D012333:RNA, Messenger; D012336:RNA, Ribosomal, 16S; C041460:peptide chain termination release factor 2