title: Effects of ribosome dissociation on the structure of the ribosome-associated 5.8S RNA.
abstract: Diethyl pyrocarbonate reactivity and thermal denaturation were used to probe potential ribosomal interactions between tRNA and the small 5.8S and 5S rRNAs. Puromycin, an analogue of the terminal aminoacyl-adenosine portion of aminoacyl-tRNA, was observed to increase the accessibility of the 5.8S rRNA, including the highly conserved GAACp sequences. EDTA which releases both tRNA and the 5S rRNA-protein complex resulted in an even greater accessibility in the 5.8S rRNA. The thermal dissociation of whole ribosomes resulted in the release of all three RNAs, with a striking similarity in the denaturation profiles. These results strongly suggest an interdependence in the ribosome-associated structures of the small rRNAs and provide in situ evidence for the various 5S rRNA, 5.8S rRNA, and tRNA containing ribonucleoprotein complexes previously reconstituted through affinity chromatography.
authors.affiliation: Department of Molecular Biology and Genetics, University of Guelph, Ont., Canada.
authors.forename: A C
authors.initials: AC
authors.lastname: Lo
authors.forename: W Y
authors.initials: WY
authors.lastname: Liu
authors.forename: D E
authors.initials: DE
authors.lastname: Culham
authors.forename: R N
authors.initials: RN
authors.lastname: Nazar
mesh_terms: D001483:Base Sequence; D004047:Diethyl Pyrocarbonate / Q000494:pharmacology; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D011691:Puromycin / Q000494:pharmacology; D012335:RNA, Ribosomal / Q000648:ultrastructure*; D012340:RNA, Ribosomal, 5.8S / Q000187:drug effects / Q000648:ultrastructure*; D012341:RNA, Ribosomal, 5S / Q000187:drug effects / Q000648:ultrastructure; D012270:Ribosomes / Q000187:drug effects / Q000648:ultrastructure*; D012441:Saccharomyces cerevisiae / Q000648:ultrastructure; D013816:Thermodynamics
chemical_list: D012335:RNA, Ribosomal; D012340:RNA, Ribosomal, 5.8S; D012341:RNA, Ribosomal, 5S; D011691:Puromycin; D004047:Diethyl Pyrocarbonate