Exchange of DNA Base Pairs that Coincides with Recognition of Homology Promoted by E. coli RecA Protein
| Autor: | Karen S. Anderson, Charles M. Radding, Shawn M. O'Malley, Ewa Folta-Stogniew, Ravindra C. Gupta |
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| Rok vydání: | 2004 |
| Předmět: |
DNA
Bacterial Base pair Stereochemistry DNA Single-Stranded Biology Genetic recombination Homology (biology) Dissociation (chemistry) 03 medical and health sciences chemistry.chemical_compound D-loop Sequence Homology Nucleic Acid Base Pairing Molecular Biology 030304 developmental biology chemistry.chemical_classification Base Composition 0303 health sciences Base Sequence Escherichia coli Proteins 030302 biochemistry & molecular biology Cell Biology Kinetics Rec A Recombinases Enzyme chemistry Biochemistry Coding strand DNA |
| Zdroj: | Molecular Cell. 15(6):965-975 |
| ISSN: | 1097-2765 |
| DOI: | 10.1016/j.molcel.2004.08.017 |
| Popis: | The unresolved mechanism by which a single strand of DNA recognizes homology in duplex DNA is central to understanding genetic recombination and repair of double-strand breaks. Using stopped-flow fluorescence we monitored strand exchange catalyzed by E. coli RecA protein, measuring simultaneously the rate of exchange of A:T base pairs and the rates of formation and dissociation of the three-stranded intermediates called synaptic complexes. The rate of exchange of A:T base pairs was indistinguishable from the rate of formation of synaptic complexes, whereas the rate of displacement of a single strand from complexes was five to ten times slower. This physical evidence shows that a subset of bases exchanges at a rate that is fast enough to account for recognition of homology. Together, several studies suggest that a mechanism governed by the dynamic structure of DNA and catalyzed by diverse enzymes underlies both recognition of homology and initiation of strand exchange. |
| Databáze: | OpenAIRE |
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