Single Nucleotide Patch Base Excision Repair Is the Major Pathway for Removal of Thymine Glycol from DNA in Human Cell Extracts
| Autor: | Tanja Thybo, Grigory L. Dianov, Leonora J. Lipinski, Vilhelm A. Bohr, Irina I. Dianova |
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| Rok vydání: | 2000 |
| Předmět: |
Xeroderma pigmentosum
DNA Repair DNA repair Molecular Sequence Data Restriction Mapping Biology Biochemistry Cell Line medicine Humans Molecular Biology Xeroderma Pigmentosum Base Sequence Mutagenesis DNA Cell Biology Base excision repair Fibroblasts medicine.disease Molecular biology Very short patch repair DNA glycosylase Excinuclease Thymine Nucleotide excision repair |
| Zdroj: | Journal of Biological Chemistry. 275:11809-11813 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.275.16.11809 |
| Popis: | The repair pathways involved in the removal of thymine glycol (TG) from DNA by human cell extracts have been examined. Closed circular DNA constructs containing a single TG at a defined site were used as substrates to determine the patch size generated after in vitro repair by cell extracts. Restriction analysis of the repair incorporation in the vicinity of the lesion indicated that the majority of TG was repaired through the base excision repair (BER) pathways. Repair incorporation 5' to the lesion, characteristic for the nucleotide excision repair pathway, was not found. More than 80% of the TG repair was accomplished by the single-nucleotide repair mechanism, and the remaining TGs were removed by the long patch BER pathway. We also analyzed the role of the xeroderma pigmentosum, complementation group G (XPG) protein in the excision step of BER. Cell extracts deficient in XPG protein had an average 25% reduction in TG incision. These data show that BER is the primary pathway for repair of TG in DNA and that XPG protein may be involved in repair of TG as an accessory factor. |
| Databáze: | OpenAIRE |
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