FIG. 5.

CpxP is the most inducible regulon member. β-Galactosidase activities were measured for PAD279 (lanes 1 and 2), PAD280 (lanes 3 and 4), PAD281 (lanes 5 and 6), PAD282 (lanes 7 and 8), PAD283 (lanes 9 and 10), and PAD593 (lanes 11 and 12) in sodium phosphate-buffered LB broth at pHs 5.5 (gray bars) and 8.5 (black bars). cpxP transcription is induced ∼15-fold by alkaline pH, while the other fusions tested were only induced between 2- and 4-fold. All strains were grown as described in Materials and Methods.