Figure 2

Induction of the expression of ohr and ohrR by peroxides. Cells were grown in LB medium to an OD_{570 nm} of 0.4. ohr::lacZ (β-galactosidase) and ohrR::uidA (β-glucuronidase) expression was analysed 2 and 3 h after OHP addition. No addition (closed diamonds), 0.25 mM CuOOH (closed triangles), 1.6 mM tBOOH (open squares), 10 mM H₂O₂ (open circles). Enzymatic activities are expressed as nmole of substrate hydrolysed per min and per mg of protein. Results are the average of four independent experiments; the standard deviation is indicated by bars.