Differential modes of DNA binding by mismatch uracil DNA glycosylase from Escherichia coli: implications for abasic lesion processing and enzyme communication in the base excision repair pathway
| Autor: | Seden Grippon, Paul M. W. French, Christopher Dunsby, Jacqueline J. T. Marshall, Gordon T. Kennedy, Mark A. A. Neil, Hugh B. Manning, Rory J. O’Neill, Geoff S. Baldwin, Stephen E. Halford, Tom Robinson, Qiyuan Zhao |
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| Rok vydání: | 2010 |
| Předmět: |
MECHANISM
STIMULATION Biochemistry & Molecular Biology DNA Repair DNA repair DNA damage Fluorescence Polarization INITIAL STEPS Sodium Chloride Genome Integrity Repair and Replication Binding Competitive AP endonuclease SUBSTRATE RECOGNITION Genetics Escherichia coli AP-ENDONUCLEASE AP site CRYSTAL-STRUCTURE Uracil-DNA Glycosidase SPECIFICITY Science & Technology COMPLEX biology Escherichia coli Proteins 8-OXOGUANINE-DNA GLYCOSYLASE Base excision repair DNA Thymine DNA Glycosylase Biochemistry DNA glycosylase Uracil-DNA glycosylase SIMPLEX-VIRUS TYPE-1 biology.protein Thymine-DNA glycosylase Life Sciences & Biomedicine DNA Damage Protein Binding |
| Zdroj: | Nucleic Acids Research |
| ISSN: | 1362-4962 |
| Popis: | Mismatch uracil DNA glycosylase (Mug) from Escherichia coli is an initiating enzyme in the base-excision repair pathway. As with other DNA glycosylases, the abasic product is potentially more harmful than the initial lesion. Since Mug is known to bind its product tightly, inhibiting enzyme turnover, understanding how Mug binds DNA is of significance when considering how Mug interacts with downstream enzymes in the base-excision repair pathway. We have demonstrated differential binding modes of Mug between its substrate and abasic DNA product using both band shift and fluorescence anisotropy assays. Mug binds its product cooperatively, and a stoichiometric analysis of DNA binding, catalytic activity and salt-dependence indicates that dimer formation is of functional significance in both catalytic activity and product binding. This is the first report of cooperativity in the uracil DNA glycosylase superfamily of enzymes, and forms the basis of product inhibition in Mug. It therefore provides a new perspective on abasic site protection and the findings are discussed in the context of downstream lesion processing and enzyme communication in the base excision repair pathway. |
| Databáze: | OpenAIRE |
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