Mutation spectrum of the mutagen 3-N,N-acetoxyacetylamino-4,6-dimethyldipyrido[1,2-a:3',2'- d]imidazole in Escherichia coli.

The mutation frequency and mutation spectrum resulting from 3-N-acetylamino-4,6-dimethyldipyrido[1,2-a:3',2'-d]imidazole (AGluP3) DNA adducts using a previously developed forward mutation assay were established. AGluP3-induced mutagenesis requires the umuC gene product(s) and exhibits similar amounts of base pair substitution and frameshift mutation. Comparison between these results and those obtained with the isosteric amine 2-N-acetylaminofluorene suggests the involvement of deacetylated adduct in the molecular mechanisms of AGluP3-induced mutagenesis.