title: RNA stem stability in the formation of a self-cleaving hammerhead structure.
abstract: The proposed single-hammerhead structure of the self-cleaving newt RNA is unstable due to a weak stem III and therefore is unable to mediate self-cleavage. A double-hammerhead structure with greater theoretical stability has been shown to mediate the self-cleavage of this RNA (Forster et al., 1988, Nature 334, 265). We have found that the double-hammerhead mediated self-cleavage reaction of a 40 base RNA containing the newt sequence (termed nCG) can be converted to a single-hammerhead reaction by increasing the size of stem III and/or of its loop, thereby enabling a single-hammerhead structure to form. In addition, the 5'-self-cleavage fragment of the nCG RNA can act in trans to mediate the self-cleavage of a full-length RNA by the formation of a partial double-hammerhead structure.
authors: Department of Biochemistry, University of Adelaide, Australia.
authors: C C
authors: CC
authors: Sheldon
authors: R H
authors: RH
authors: Symons
mesh_terms: D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides; D012313:RNA / Q000138:chemical synthesis / Q000378:metabolism / Q000648:ultrastructure*; D013604:T-Phages / Q000201:enzymology; D014158:Transcription, Genetic
chemical_list: D009838:Oligodeoxyribonucleotides; D012313:RNA; D012321:DNA-Directed RNA Polymerases