FIG 6 .

GbdR binds the caiX-cdhR intergenic region but does not induce transcription of caiX. (A) EMSAs were performed with increasing concentrations of purified MBP-GbdR with either the biotin-labeled cdhR wild-type probe or a mutant binding site probe. The mutated probe has the distal half-site CG residues (in relation to cdhR) changed to AA. (B) β-Galactosidase assay with a caiX-lacZ reporter plasmid (pJAM22) in wild-type, ΔcdhR, ΔgbdR, or ΔcdhR ΔgbdR strains of both PA14 (14) and PAO1 (1) grown in MOPS, 20 mM pyruvate, and 20 µg·ml⁻¹ gentamicin. Induced cultures have an additional 1 mM carnitine. Error bars represent standard deviations from three biological replicates, and results are representative of three independent experiments. Data were analyzed with two-way ANOVA with a Tukey’s multiple-comparison test comparing all mutants and conditions within a given strain. (PA14 was not compared to PAO1.) Abbreviations: ***, P < 0.001 compared to WT with pyruvate; #, P < 0.01 compared to WT with carnitine.