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Oxidative base damage to DNA: specificity of base excision repair enzymes
Base excision repair (BER) is likely to be the main mechanism involved in the enzymatic restoration of oxidative base lesions within the DNA of both prokaryotic and eukaryotic cells. Emphasis was placed in early studies on the determination of the ability of several bacterial DNA N-glycosylases, inc...
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Published in: | Mutation research. Reviews in mutation research 2000-04, Vol.462 (2), p.121-128 |
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Main Authors: | , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Base excision repair (BER) is likely to be the main mechanism involved in the enzymatic restoration of oxidative base lesions within the DNA of both prokaryotic and eukaryotic cells. Emphasis was placed in early studies on the determination of the ability of several bacterial DNA
N-glycosylases, including
Escherichia coli endonuclease III (endo III) and formamidopyrimidine DNA
N-glycosylase (Fpg), to recognize and excise several oxidized pyrimidine and purine bases. More recently, the availability of related DNA repair enzymes from yeast and human has provided new insights into the enzymatic removal of several
·
OH
-mediated modified DNA bases. However, it should be noted that most of the earlier studies have involved globally modified DNA as the substrates. This explains, at least partly, why there is a paucity of accurate kinetic data on the excision rate of most of the modified bases. Interestingly, several oxidized pyrimidine and purine nucleosides have been recently inserted into defined sequence oligonucleotides. The use of the latter substrates, together with overexpressed DNA
N-glycosylases, allows detailed studies on the efficiency of the enzymatic release of the modified bases. This was facilitated by the development of accurate chromatographic and mass spectrometric methods aimed at measuring oxidized bases and nucleosides. As one of the main conclusions, it appears that the specificity of both endo III and Fpg proteins is much broader than expected a few years ago. |
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ISSN: | 1383-5742 1388-2139 |
DOI: | 10.1016/S1383-5742(00)00022-3 |