PMID:8676878
| Citation |
Bridges, BA, Sekiguchi, M and Tajiri, T (1996) Effect of mutY and mutM/fpg-1 mutations on starvation-associated mutation in Escherichia coli: implications for the role of 7,8-dihydro-8-oxoguanine. Mol. Gen. Genet. 251:352-7 |
|---|---|
| Abstract |
MutY specifies a DNA glycosylase that removes adenines unnaturally paired with various bases including oxidized derivatives of guanine, such as 7,8-dihydro-8-oxoguanine (8-oxoG). The rate of mutation in starved Escherichia coli cells is markedly raised in mutY mutants defective in this glycosylase. As predicted, the mutations produced include G to T transversions. Bacteria carrying mutM or fpg-1 mutations (defective in Fapy glycosylase, which removes oxidized guanine residues such as 8-oxoG) show little or no enhancement of mutation under starvation conditions. When present together with mutY, however, mutM clearly further enhances the rate of mutation in starved cells. Plasmids resulting in overproduction of MutY or Fapy glycosylases reduce the rate of mutation in starved cells. We conclude that, in non-growing bacteria, oxidized guanine residues, including 8-oxoG, constitute an important component of spontaneous mutation. Addition of catalase to the plates did not reduce the mutant yield, indicating that extracellular hydrogen peroxide is not involved in the production of the premutational damage. Singlet oxygen, known to give rise to 8-oxoG, may be the ultimate oxidative species. |
| Links | |
| Keywords |
Catalase/pharmacology; DNA Glycosylases; DNA, Bacterial/chemistry; DNA, Bacterial/genetics; DNA-Formamidopyrimidine Glycosylase; Escherichia coli/genetics; Escherichia coli/growth & development; Escherichia coli Proteins; Guanine/analogs & derivatives; Guanine/physiology; Mutagenesis/physiology; N-Glycosyl Hydrolases/biosynthesis; N-Glycosyl Hydrolases/genetics; N-Glycosyl Hydrolases/physiology; Point Mutation |
| 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)
See also
References
See Help:References for how to manage references in EcoliWiki.