FIG. 5.

Genetic maps and transcripts of OxyR-regulated genes. The katB, ahpB, and ahpC-ahpF loci are shown with their coordinates in the PAO1 genome (Pathogenesis Corp., 12-15-99 release), the sites of insertions or deletions in the corresponding mutants, the locations of the riboprobes (rp), and relevant restriction sites. The katB-ankB operon encodes a previously characterized inducible catalase (6) and an ankyrin-like factor required for optimal catalase activity (24). The ahpB gene encodes a thiol-specific peroxidase and is located upstream of a thioredoxin reductase (tdr). The ahpC-ahpF operon encodes the two subunits of the classic alkyl hydroperoxide reductase. The RNase protection assays were done with total RNA isolated from PAO1 wild-type or oxyR mutant cells in the absence or presence of paraquat (PQ) as indicated. A probe specific for the constitutively expressed omlA gene (39) was used as a control. Also loaded were diluted probes (rp) and the digested probes (rp*) as controls. Arrows point to the relevant protected riboprobe bands, and their approximate sizes (in nucleotides) are given.