title: Molecular model for 5-S RNA. A small-angle x-ray scattering study of native, denatured and aggregated 5-S RNA from Escherichia coli ribosomes.
abstract: A tertiary structural model is suggested for Escherichia coli 5-S RNA that consists of one large and two small double helices arranged in the form of the letter Y. This model is consistent with the small-angle X-ray scattering data of native 5-S RNA, measured in the angular range 20 less than or equal to 140 mrad. The radium of gyration is 3.61 +- 0.1 Nm. Denatured 5-S RNA yields a much lower radius of gyration, 2.7 nm, which might indicate that during denaturation one minor double-helical arm of the Y-shaped structure partially collapses into single-stranded areas. At high concentrations (60 mg/ml) of 5-S RNA, the X-ray scattering data indicate that 5-S RNA is aggregated.
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D004926:Escherichia coli / Q000032:analysis*; D046911:Macromolecular Substances; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D012335:RNA, Ribosomal; D012270:Ribosomes / Q000032:analysis; D014961:X-Ray Diffraction
chemical_list: D046911:Macromolecular Substances; D012335:RNA, Ribosomal