FIG. 7.

Genes controlled by σ^W are overexpressed in B. subtilis ftsH knockout strains. (A) Strains with a transcriptional fusion of the σ^W-controlled yuaF promoter to lacZ were grown at 37°C in LB medium. At different time points, samples were withdrawn and β-galactosidase activities were determined. Circles, B. subtilis TW51 (amyE::P_yuaF-lacZ); squares, TW52 (amyE::P_yuaF-lacZ ftsH::cat). Open symbols, OD₅₇₈; solid symbols, β-galactosidase activity. (B) B. subtilis strain MSW01 (sigW⁺ pX2-ftsH) was grown in the absence (lane 1) or presence (lane 2) of xylose to mid-logarithmic phase and analyzed by Western blotting using antibodies against FtsH and YdjF. B. subtilis 1012 (wild type) grown without xylose (lane 3) was used as a control. (C) Schematic representation of DNA macroarray analysis of B. subtilis 1012 ftsH::cat compared to that of the wild type. DNA arrays of the entire B. subtilis genes were hybridized with cDNA probes generated from RNA extracted from cells of the two strains at an OD₅₇₈ of 0.8. Mean results and standard deviations from two independent experiments are presented. Spot intensities were quantified as described previously (37), and the quotients of ftsH::cat/wild-type intensities for σ^W-controlled genes are given.