Imidazole rescue of a cytosine mutation in a self-cleaving ribozyme.
Journal Article (Journal Article)
Ribozymes use a number of the same catalytic strategies as protein enzymes. However, general base catalysis by a ribozyme has not been demonstrated. In the hepatitis delta virus antigenomic ribozyme, imidazole buffer rescued activity of a mutant with a cytosine-76 (C76) to uracil substitution. In addition, a C76 to adenine substitution reduced the apparent pKa (where Ka is the acid constant) of the self-cleavage reaction by an amount consistent with differences in the pKa values of these two side chains. These results suggest that, in the wild-type ribozyme, C76 acts as a general base. This finding has implications for potential catalytic functions of conserved cytosines and adenines in other ribozymes and in ribonuclear proteins with enzymatic activity.
Full Text
Duke Authors
Cited Authors
- Perrotta, AT; Shih, I; Been, MD
Published Date
- October 1, 1999
Published In
Volume / Issue
- 286 / 5437
Start / End Page
- 123 - 126
PubMed ID
- 10506560
International Standard Serial Number (ISSN)
- 0036-8075
Digital Object Identifier (DOI)
- 10.1126/science.286.5437.123
Language
- eng
Conference Location
- United States