The P. aeruginosa mexAB-oprM operon was selected for investigation, and EMSA demonstrated specific binding of mexR to three sites upstream of the mexR gene, but none upstream of mexA. DNase I assay identified two protected regions, designated Site I and II, consistent with the EMSA. RACE and RT-PCR of Site II in wild-type and mutant strains both confirmed the down-regulation of mexAB-oprM upon mexR binding.
Regulated genes for each binding site are displayed below. Gene regulation diagrams show binding sites, positively-regulated genes, negatively-regulated genes, both positively and negatively regulated genes, genes with unspecified type of regulation. For each indvidual site, experimental techniques used to determine the site are also given.
|Site sequence||Regulated genes||Gene diagram||Experimental techniques||TF function||TF type|