title: Role of a conserved J8/7 X P4 base-triple in the Tetrahymena ribozyme.
abstract: The Tetrahymena group I intron ribozyme folds into a complex three dimensional structure for performing the self-splicing reaction. Catalysis depends on its core structure comprising two helical domains, P4-P6 and P3-P7. The two domains are joined by three sets of conserved base-triple(s) and other tertiary interactions. We found that the disruption of J8/7 X P4, one such conserved base-triple, causes the catalytic ability to deteriorate without altering the folding rate. This suggests that the base-triple stabilizes the active structure of the ribozyme but plays no significant role in RNA folding. By combining the present and previous results, it can be concluded that three sets of conserved base-triples play distinct roles in the Tetrahymena ribozyme.
authors.affiliation: Graduate School of Biostudies, Kyoto University, Kyoto 606-8502.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ohki
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Ikawa
authors.forename: Hideaki
authors.initials: H
authors.lastname: Shiraishi
authors.forename: Tan
authors.initials: T
authors.lastname: Inoue
mesh_terms: D000818:Animals; D001483:Base Sequence; D017124:Conserved Sequence; D007438:Introns / Q000235:genetics* / Q000502:physiology; D009154:Mutation; D009690:Nucleic Acid Conformation; D016337:RNA, Catalytic / Q000235:genetics* / Q000378:metabolism; D013768:Tetrahymena / Q000201:enzymology / Q000235:genetics*
chemical_list: D016337:RNA, Catalytic