title: Hyperresistance to DNA damaging agents in yeast.
abstract: In order to study resistance to DNA damaging agents, yeast DNA segments conferring hyperresistance in this organism to such genotoxic agents were selected for among yeast cells transformed by a yeast genome library based on the multi-copy vector plasmid YEp13. Genetic variants hyperresistant to 4-nitroquinoline-N-oxide, formaldehyde, and alkylating agents were isolated and the respective hyperresistance determinants shown to co-segregate with the vector plasmid. Phenotypical characterization indicated different degrees of resistance, few cases of cross-resistance and differing structural stability of the cloned DNA. By transfer to E. coli and subsequent retransformation of yeast a number of plasmids was shown to stably carry the genetic information for hyperresistance.
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000494:pharmacology; D004249:DNA Damage; D004352:Drug Resistance, Microbial; D005557:Formaldehyde / Q000494:pharmacology; D008466:Mechlorethamine / Q000494:pharmacology; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D010641:Phenotype; D011815:R Factors; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics*
chemical_list: D008769:Methylnitronitrosoguanidine; D005557:Formaldehyde; D008466:Mechlorethamine; D015112:4-Nitroquinoline-1-oxide