title: RNA as an enzyme.
abstract: The catalytic activity of ribonucleic acid is reviewed, with the intervening sequence (IVS) of the ribosomal RNA precursor of Tetrahymena serving as a major example. The IVS catalyzes its own excision from the precursor RNA and at the same time ligation of the flanking sequences, a reaction termed self-splicing. The excised IVS RNA can act as an enzyme to catalyze sequence-specific cleavage and ligation reactions on substrate RNA molecules. The RNA polymerization activity of the IVS supports the possibility that RNA catalysis could have been important in establishing a prebiotic self-replicating system. Other systems in which RNA catalysis has been found include related group I IVSs, group II IVSs, ribonuclease P, and certain plant infectious RNAs.
authors: Howard Hughes Medical Institute, Department of Chemistry and Biochemistry, University of Colorado, Boulder 80309-0215.
authors: T R
authors: TR
authors: Cech
mesh_terms: D000818:Animals; D002384:Catalysis; D004798:Enzymes; D007438:Introns; D012313:RNA / Q000378:metabolism*; D012326:RNA Splicing; D016337:RNA, Catalytic; D012335:RNA, Ribosomal / Q000378:metabolism; D013768:Tetrahymena / Q000378:metabolism
chemical_list: D004798:Enzymes; D016337:RNA, Catalytic; D012335:RNA, Ribosomal; D012313:RNA