PMID:11328881
| Citation |
Hazra, TK, Muller, JG, Manuel, RC, Burrows, CJ, Lloyd, RS and Mitra, S (2001) Repair of hydantoins, one electron oxidation product of 8-oxoguanine, by DNA glycosylases of Escherichia coli. Nucleic Acids Res. 29:1967-74 |
|---|---|
| Abstract |
8-oxoguanine (8-oxoG), induced by reactive oxygen species and arguably one of the most important mutagenic DNA lesions, is prone to further oxidation. Its one-electron oxidation products include potentially mutagenic guanidinohydantoin (Gh) and spiroiminodihydantoin (Sp) because of their mispairing with A or G. All three oxidized base-specific DNA glycosylases of Escherichia coli, namely endonuclease III (Nth), 8-oxoG-DNA glycosylase (MutM) and endonuclease VIII (Nei), excise Gh and Sp, when paired with C or G in DNA, although Nth is less active than the other two. MutM prefers Sp and Gh paired with C (kcat/K(m) of 0.24-0.26 min(-1) x nM(-1)), while Nei prefers G over C as the complementary base (k(cat)/K(m) - 0.15-0.17 min(-1) x nM(-1)). However, only Nei efficiently excises these paired with A. MutY, a 8-oxoG.A(G)-specific A(G)-DNA glycosylase, is inactive with Gh(Sp).A/G-containing duplex oligonucleotide, in spite of specific affinity. It inhibits excision of lesions by MutM from the Gh.G or Sp.G pair, but not from Gh.C and Sp.C pairs. In contrast, MutY does not significantly inhibit Nei for any Gh(Sp) base pair. These results suggest a protective function for MutY in preventing mutation as a result of A (G) incorporation opposite Gh(Sp) during DNA replication. |
| Links | |
| Keywords |
DNA Glycosylases; DNA Repair; DNA-Formamidopyrimidine Glycosylase; Deoxyribonuclease (Pyrimidine Dimer); Electrons; Endodeoxyribonucleases/chemistry; Endodeoxyribonucleases/metabolism; Enzyme Inhibitors/chemistry; Enzyme Inhibitors/pharmacology; Escherichia coli/enzymology; Escherichia coli Proteins; Guanidines/chemistry; Guanidines/metabolism; Guanine/analogs & derivatives; Guanine/chemistry; Guanine/metabolism; Guanosine/analogs & derivatives; Guanosine/chemistry; Guanosine/metabolism; Hydantoins/chemistry; Hydantoins/metabolism; Kinetics; N-Glycosyl Hydrolases/antagonists & inhibitors; N-Glycosyl Hydrolases/chemistry; N-Glycosyl Hydrolases/metabolism; Oxidation-Reduction; Protein Binding; Schiff Bases/chemistry; Spiro Compounds/chemistry; Spiro Compounds/metabolism; Substrate Specificity |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.