title: Effect of genotype on mutagenicity of niridazole in nitroreductase-deficient bacteria.
abstract: The mutagenicity of niridazole for Salmonella typhimurium depends upon the enzymic reduction of the nitro function. The response of niridazole nitroreductase-deficient bacteria to niridazole is reduced to 4.4 and 0.19% that exhibited by the enzyme-proficient parent strain when the deficiency is the result of a base substitution and frame-shift mutation, respectively. The results are taken to indicate that the residual activity (4.4%) seen in the strain with a base substitution mutation reflects the activity of an enzyme with an amino acid substitution, while the basal level (0.19%) of activity indicates the action of a different nitroreductase with a low specificity for niridazole.
mesh_terms: D005838:Genotype; D009153:Mutagens; D009154:Mutation / Q000187:drug effects; D009560:Niridazole / Q000494:pharmacology*; D010088:Oxidoreductases / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics
chemical_list: D009153:Mutagens; D010088:Oxidoreductases; D009560:Niridazole