RESUMO
Saccharomyces cerevisiae is an ideal eukaryotic unicell system for the study of the 'damage and repair'. In order to understand the genetics and mechanism of adaptive repair to alkylation stress the isolation and characterization of ada mutants [like ngs] bear important implications. We report for an ethyl methane sulfonate [EMS] - induced ngs MR0192 mutant of S. cerevisiae. The mutant cells showed a decreased survival after nitrosoguanidine [MNNG] treatment [doses >1.5 micro g mL -1 proved lethal] compared to is its parent strain [that survived upto 5 micro g mL -1] and failed to manifest adaptive repair. This ada mutant suffered from a cumulative effect of MNNG dose and cyclohexamide protein synthesis inhibitor]. The results have helped to elucidate the role of ada gene in alkylation mediated repair in S. cerevisiae