FIG. 2.

DNA damage sensitivity of recU replicating cells. The survival of wt cells (open symbols) and recU40 cells (filled symbols) (A), and of recR13 cells (open symbols) and uvrA42 control cells (filled symbols) (B) after exposure to the killing action of 100 μM 4NQO under different growth conditions is shown. Triangles, stationary-phase cells; circles, exponential-phase growing cells; squares, cells pretreated with CM (20 μg/ml) 120 min before 4NQO treatment. Survival curves represent the averages of results of three or more independent experiments.