FIG. 5.

RNase protection assays indicate that katB and ankB comprise an operon and are regulated by OxyR. Riboprobes specific for the katB promoter (katB rp) and for the katB-ankB overlapping region (katB-ankB rp) were used to detect the corresponding transcripts in P. aeruginosa PAO1 or oxyR mutant total RNA isolated during the exponential growth phase in aerobic M9 minimal medium. Paraquat (PQ) was added to final concentrations of 10 and 100 μM 1 h prior to harvest as indicated. Also shown are the digested probes in the absence of any P. aeruginosa RNA as a control. A DNA sequencing reaction was run in parallel and served as a size marker. Numbers on the left are base pairs.