Figure 6.

Suppression of sensitivity of the radA recG strain to DNA damaging agents by overexpression of ruvAB. Wild-type (circles), radA (triangles), recG (squares) or radA recG (inverted triangles) strains were transformed with pGB2 vector (open symbols) or pGB-ruvAB (closed symbols). The resulting strains were grown to early log phase in LB medium containing 100 g ml⁻¹ streptomycin and plated on LB medium followed by UV irradiation or on LB medium containing ciprofloxacin or AZT. Plates were incubated at 37° and surviving colonies were counted after 18–36 hours. Mean fractional survival of at least eight different cultures plated on two different days is shown with the error bars representing the standard deviation of the mean.