GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com


Jump to: navigation, search

Ramotar, D, Popoff, SC, Gralla, EB and Demple, B (1991) Cellular role of yeast Apn1 apurinic endonuclease/3'-diesterase: repair of oxidative and alkylation DNA damage and control of spontaneous mutation. Mol. Cell. Biol. 11:4537-44


The APN1 gene of Saccharomyces cerevisiae encodes the major apurinic/apyrimidinic endonuclease and 3'-repair DNA diesterase in yeast cell extracts. The Apn1 protein is a homolog of Escherichia coli endonuclease IV, which functions in the repair of some oxidative and alkylation damages in that organism. We show here that yeast strains lacking Apn1 (generated by targeted gene disruption or deletion-replacement) are hypersensitive to both oxidative (hydrogen peroxide and t-butylhydroperoxide) and alkylating (methyl- and ethylmethane sulfonate) agents that damage DNA. These cellular hypersensitivities are correlated with the accumulation of unrepaired damages in the chromosomal DNA of apn1 mutant yeast cells. Hydrogen peroxide-treated APN1+ but not apn1 mutant cells regenerate high-molecular-weight DNA efficiently after the treatment. The DNA strand breaks that accumulate in the Apn1-deficient mutant contain lesions that block the action of DNA polymerase but can be removed in vitro by purified Apn1. An analogous result with DNA from methylmethane sulfonate-treated cells corresponded to the accumulation of unrepaired DNA apurinic sites in the apn1 mutant cells. The rate of spontaneous mutation in apn1 mutant S. cerevisiae was 6- to 12-fold higher than that measured for wild-type yeast cells. This increase indicates that under normal growth conditions, the production of DNA damages that are targets for Apn1 is substantial and that such lesions can be mutagenic when left unrepaired.


PubMed PMC361329


Alkylating Agents/pharmacology; Alkylation; Centrifugation, Density Gradient; DNA Damage; DNA-(Apurinic or Apyrimidinic Site) Lyase; DNA-Directed DNA Polymerase/metabolism; Deoxyribonuclease IV (Phage T4-Induced); Endodeoxyribonucleases/metabolism; Escherichia coli Proteins; Genes, Fungal; Hydrogen Peroxide/pharmacology; Methyl Methanesulfonate/pharmacology; Mutation; Oxidation-Reduction; Saccharomyces cerevisiae/drug effects; Saccharomyces cerevisiae/enzymology; Saccharomyces cerevisiae/genetics



Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status


GO:0004520: endodeoxyribonuclease activity



Figure 7

CACAO 9126

See also


See Help:References for how to manage references in GONUTS.