title: Do the hairpin and VS ribozymes share a common catalytic mechanism based on general acid-base catalysis? A critical assessment of available experimental data.
abstract: The active centers of the hairpin and VS ribozymes are both generated by the interaction of two internal loops, and both ribozymes use guanine and adenine nucleobases to accelerate cleavage and ligation reactions. The centers are topologically equivalent and the relative positioning of key elements the same. There is good evidence that the cleavage reaction of the VS ribozyme is catalyzed by the guanine (G638) acting as general base and the adenine (A756) as general acid. We now critically evaluate the experimental mechanistic evidence for the hairpin ribozyme. We conclude that all the available data are fully consistent with a major contribution to catalysis by general acid-base catalysis involving the adenine (A38) and guanine (G8). It appears that the two ribozymes are mechanistically equivalent.
authors.affiliation: Cancer Research UK Nucleic Acid Structure Research Group, MSI/WTB Complex, The University of Dundee, Dundee DD15EH, United Kingdom.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Wilson
authors.forename: David M J
authors.initials: DM
authors.lastname: Lilley
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D002384:Catalysis; D020134:Catalytic Domain; D004722:Endoribonucleases / Q000737:chemistry*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016337:RNA, Catalytic / Q000737:chemistry*; D013379:Substrate Specificity
chemical_list: D016337:RNA, Catalytic; C418481:hairpin ribozyme; D004722:Endoribonucleases; C438195:varkud satellite ribozyme