Abstract
Four RNA motifs are known that catalyse site-specific cleavage in the presence of Mg2+ ions, all discovered in natural RNAs. In a single in vitro selection experiment we have isolated representatives of five novel classes of Mg(2+)-dependent ribozymes. Small versions of three of these showed that a very simple internal loop type of secondary structure is responsible for the activity. One of these was synthesized in a bimolecular form, and compared directly with the hammerhead ribozyme; for the new ribozyme, the cleavage step of the reaction is much faster than the spontaneous rate of phosphodiester bond cleavage, yet substantially slower than that for the hammerhead. The results suggest that many more Mg(2+)-dependent self-cleaving RNA sequences can be found.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Baldi M. I., Mattoccia E., Bufardeci E., Fabbri S., Tocchini-Valentini G. P. Participation of the intron in the reaction catalyzed by the Xenopus tRNA splicing endonuclease. Science. 1992 Mar 13;255(5050):1404–1408. doi: 10.1126/science.1542788. [DOI] [PubMed] [Google Scholar]
- Dahm S. C., Derrick W. B., Uhlenbeck O. C. Evidence for the role of solvated metal hydroxide in the hammerhead cleavage mechanism. Biochemistry. 1993 Dec 7;32(48):13040–13045. doi: 10.1021/bi00211a013. [DOI] [PubMed] [Google Scholar]
- Fedor M. J., Uhlenbeck O. C. Kinetics of intermolecular cleavage by hammerhead ribozymes. Biochemistry. 1992 Dec 8;31(48):12042–12054. doi: 10.1021/bi00163a012. [DOI] [PubMed] [Google Scholar]
- Pan T., Dichtl B., Uhlenbeck O. C. Properties of an in vitro selected Pb2+ cleavage motif. Biochemistry. 1994 Aug 16;33(32):9561–9565. doi: 10.1021/bi00198a023. [DOI] [PubMed] [Google Scholar]
- Phizicky E. M., Greer C. L. Pre-tRNA splicing: variation on a theme or exception to the rule? Trends Biochem Sci. 1993 Jan;18(1):31–34. doi: 10.1016/0968-0004(93)90085-2. [DOI] [PubMed] [Google Scholar]