Toxicity and tolerance mechanisms for azidothymidine, a replication gap-promoting agent, in Escherichia coli

▶ AZT causes replication arrest in the bacterium, E. coli. ▶ AZT produces ssDNA gaps. ▶ AZT induces gap-filling recombination reactions. ▶ Exonuclease III is implicated in AZT removal, not proof-reading exonucleases. ▶ AZT is processed to double-strand breaks.