Physical and functional interactions between Escherichia coli MutL and the Vsr repair endonuclease
| Autor: | Bernard A. Connolly, Claire G. Cupples, Roger J. Heinze, Luis Giron-Monzon, Sven Geisler, Alexandra Solovyova, Sarah L. Elliot, Peter Friedhoff |
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| Rok vydání: | 2009 |
| Předmět: |
congenital
hereditary and neonatal diseases and abnormalities MutS DNA Mismatch-Binding Protein DNA repair Biology DNA-binding protein DNA Mismatch Repair 03 medical and health sciences Endonuclease chemistry.chemical_compound MutS-1 Genetics Endodeoxyribonucleases 030304 developmental biology Adenosine Triphosphatases 0303 health sciences Nucleic Acid Enzymes Escherichia coli Proteins 030302 biochemistry & molecular biology Photochemical Processes Protein Structure Tertiary DNA-Binding Proteins Cross-Linking Reagents DNA Repair Enzymes MutL Proteins chemistry biology.protein DNA mismatch repair Ultracentrifugation DNA |
| Zdroj: | Nucleic Acids Research |
| ISSN: | 1362-4962 |
| Popis: | DNA mismatch repair (MMR) and very-short patch (VSP) repair are two pathways involved in the repair of T:G mismatches. To learn about competition and cooperation between these two repair pathways, we analyzed the physical and functional interaction between MutL and Vsr using biophysical and biochemical methods. Analytical ultracentrifugation reveals a nucleotide-dependent interaction between Vsr and the N-terminal domain of MutL. Using chemical crosslinking, we mapped the interaction site of MutL for Vsr to a region between the N-terminal domains similar to that described before for the interaction between MutL and the strand discrimination endonuclease MutH of the MMR system. Competition between MutH and Vsr for binding to MutL resulted in inhibition of the mismatch-provoked MutS- and MutL-dependent activation of MutH, which explains the mutagenic effect of Vsr overexpression. Cooperation between MMR and VSP repair was demonstrated by the stimulation of the Vsr endonuclease in a MutS-, MutL- and ATP-hydrolysis-dependent manner, in agreement with the enhancement of VSP repair by MutS and MutL in vivo. These data suggest a mobile MutS–MutL complex in MMR signalling, that leaves the DNA mismatch prior to, or at the time of, activation of downstream effector molecules such as Vsr or MutH. |
| Databáze: | OpenAIRE |
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