FIG. 2.

(A) HAP-induced mutagenesis frequencies of E. coli strains mutant for suspected purine base analog-metabolizing enzymes. Mid-log-phase cells were exposed to various concentrations of HAP for 1 h at 37°C. Results for wild type and rdgB nfi were indistinguishable. (B) HAP-induced mutagenesis frequencies of NEB10 (moa rdgB) at very low HAP concentrations. Each data point represents one bacterial culture. Symbols: ○, CSH106 (wild type); •, NEB9 (moa); □, NEB10 (moa rdgB); ▪, NEB19 (moa nfi); ▵, NEB41 (moa rdgB nfi); ▴, NEB32 (rdgB nfi).