title: Complementation of DNA repair-deficient Escherichia coli by the yeast Apn1 apurinic/apyrimidinic endonuclease gene.
abstract: The Saccharomyces cerevisiae APN1 gene encoding an AP endonuclease/3'-diesterase was engineered in vitro for expression in Escherichia coli. The expression vector directs the synthesis in E. coli of a Mr 40,500 protein that reacts with anti-Apn1 antibodies and has the DNA-repair activities characteristic of Apn1 isolated from yeast. A band corresponding to Apn1 was observed in DNA repair activity gels only with extracts of E. coli harbouring the APN1 expression plasmid. Expression of Apn1 conferred resistance to oxidants and alkylating agents in E. coli lacking exonuclease III and endonuclease IV. For H2O2 damage, this rescue effect was correlated with the repair of oxidative lesions in the bacterial chromosome by the Apn1 protein. Thus, Apn1 can function in bacteria in a manner similar to its proposed multiple functions in yeast.
authors.affiliation: Laboratory of Toxicology, Harvard School of Public Health, Boston, Massachusetts 02115.
authors.forename: D
authors.initials: D
authors.lastname: Ramotar
authors.forename: S C
authors.initials: SC
authors.lastname: Popoff
authors.forename: B
authors.initials: B
authors.lastname: Demple
mesh_terms: D001483:Base Sequence; D003001:Cloning, Molecular; D004249:DNA Damage; D004260:DNA Repair / Q000235:genetics*; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D043223:Deoxyribonuclease IV (Phage T4-Induced); D004706:Endodeoxyribonucleases / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D005822:Genetic Vectors; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D013696:Temperature; D014169:Transformation, Bacterial
chemical_list: D029968:Escherichia coli Proteins; D006861:Hydrogen Peroxide; D004706:Endodeoxyribonucleases; D043223:Deoxyribonuclease IV (Phage T4-Induced); C468972:endonuclease IV, E coli; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase