FIG. 3.

Northern blot analyses of genes partly regulated by ς^B. RNA was isolated from S. aureus COL and its isogenic sigB mutant growing in LB at 37°C (lanes co) and at various times after a shift to 48°C. The membrane was hybridized with digoxigenin-labeled RNA probes for the respective genes. Relevant transcripts are indicated. Schematic representations of the gene loci based on sequences of S. aureus COL (TIGR, unpublished data) are shown (P_B, ς^B-dependent promoter; P_A, ς^A-dependent promoter). The broken lines represent the RNA probe used in the experiments whose results are shown. (A) ς^B-dependent genes monocistronically transcribed. (B) ς^B-dependent operons. We verified the operon structures of the csb10 and csb22 loci by using additional probes (csb10-1, csb10-4, and csb22-1). MM, synthetic medium.