Branch-site selection in a group II intron mediated by active recognition of the adenine amino group and steric exclusion of non-adenine functionalities
| Autor: | Arbi Khodadadi, Peter Haeberli, Leonid Beigelman, Qiaolian Liu, Anna Marie Pyle, Justin B. Green |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
chemistry.chemical_classification
Steric effects Binding Sites Adenine RNA Splicing Mutant Ribozyme Group II intron Biology Adenosine Introns chemistry Nucleophile Biochemistry Structural Biology RNA splicing Mutagenesis Site-Directed Spliceosomes medicine biology.protein RNA Catalytic Nucleotide RNA Processing Post-Transcriptional Molecular Biology medicine.drug |
| Zdroj: | Journal of Molecular Biology. 267:163-171 |
| ISSN: | 0022-2836 |
| Popis: | The 2′-hydroxyl on a specific bulged adenosine is the nucleophile during the first step of splicing by group II introns. To understand the means by which the ribozyme core recognizes this adenosine, it was mutagenized and effects on catalytic activity were quantified. The results indicate that a low level of mutational variability is tolerated at the branch-site of group II introns, with no apparent loss of fidelity. Analyses of mutant and modified nucleotides at the branch-site reveal that adenine is recognized primarily through the N6 amino group and by steric exclusion of functionalities found on other bases. The mutational and single atom effects reported here contrast with those observed during spliceosomal processing, suggesting that there are important differences in adenosine recognition by the two systems. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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