title: 5-Amino-4-imidazolecarboxamide is a mutagen in E. coli.
abstract: 5-Amino-4-imidazolecarboxamide (5A4IC), the base moiety of a common intermediate in de novo purine biosynthesis, was found to be mutagenic in E. coli. Using a series of mutants in the tryptophan synthetase A gene, 5A4IC was observed to cause transition and transversion mutations at similar levels. At 400 micrograms/ml in the growth medium, it stimulates the base substitution GC----AT 4.8-fold; AT----GC 20-fold; AT----CG (2 sites) an average of 6.0-fold; AT----TA 7.8-fold; and GC----CG 6.1-fold. The transversion GC----TA was not tested. In contrast to the base, 5-amino-4-imidazolecarboxamide riboside is not mutagenic at a similar molar concentration.
mesh_terms: D000620:Aminoimidazole Carboxamide / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D001482:Base Composition; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D005798:Genes, Bacterial / Q000187:drug effects*; D007093:Imidazoles / Q000494:pharmacology*; D009154:Mutation; D014367:Tryptophan Synthase / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D007093:Imidazoles; D000620:Aminoimidazole Carboxamide; D014367:Tryptophan Synthase