Metal ion specificities for folding and cleavage activity in the Schistosoma hammerhead ribozyme
| Autor: | Ehsan Azimi, Arthur Pardi, Marella D. Canny, Jennifer L. Boots |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Hammerhead ribozyme
Base Sequence biology Cations Divalent Metal ions in aqueous solution Kinetics Ribozyme Schistosoma mansoni biology.organism_classification Article Ion Metal Crystallography Förster resonance energy transfer Biochemistry Metals visual_art biology.protein visual_art.visual_art_medium Animals Nucleic Acid Conformation RNA Catalytic Hairpin ribozyme Molecular Biology |
| Zdroj: | RNA. 14:2212-2222 |
| ISSN: | 1469-9001 1355-8382 |
| DOI: | 10.1261/rna.1010808 |
| Popis: | The effects of various metal ions on cleavage activity and global folding have been studied in the extended Schistosoma hammerhead ribozyme. Fluorescence resonance energy transfer was used to probe global folding as a function of various monovalent and divalent metal ions in this ribozyme. The divalent metals ions Ca2+, Mg2+, Mn2+, and Sr2+ have a relatively small variation (less than sixfold) in their ability to globally fold the hammerhead ribozyme, which contrasts with the very large difference (>10,000-fold) in apparent rate constants for cleavage for these divalent metal ions in single-turnover kinetic experiments. There is still a very large range (>4600-fold) in the apparent rate constants for cleavage for these divalent metal ions measured in high salt (2 M NaCl) conditions where the ribozyme is globally folded. These results demonstrate that the identity of the divalent metal ion has little effect on global folding of the Schistosoma hammerhead ribozyme, whereas it has a very large effect on the cleavage kinetics. Mechanisms by which the identity of the divalent metal ion can have such a large effect on cleavage activity in the Schistosoma hammerhead ribozyme are discussed. |
| Databáze: | OpenAIRE |
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