PubMed · 1999 · 13 citations · 0 references
Life SciencesGeneticsMolecular BiologyDna RepairGenetic ToxicologyMicrobial GeneticsDna Adduct FormationDna DamageDna Double-strand Break RepairMutagenicity AssessmentDna Adduct MutagenicityEscherichia ColiHomologous Recombination RepairMammalian Cell Mutagenicity AssaysMutagenic EffectivenessMutagenic MechanismsRecombination Repair Pathways
The mutagenic potential of three exocyclic DNA adducts was studied in Escherichia coli and simian kidney cells by incorporating them into single-stranded DNA. Differences in the mutagenic potency of the adducts were observed between hosts: 1,N6-ethenodeoxyadenosine and 3,N4-ethenodeoxycytidine were more mutagenic in simian cells, whereas 1,N2-(1,3-propan-1,3-diyl)-2'-deoxyguanosine was more mutagenic in E. coli. To investigate the cellular response to DNA adducts, a double-stranded DNA vector system was developed. Use of this system showed that 1,N6-ethenodeoxyadenosine blocks DNA synthesis strongly, and DNA synthesis past this adduct was highly accurate in E. coli. The blockage of DNA synthesis was overcome in an error-free manner by the recombination repair mechanism (daughter-strand gap repair).