DNase I footprinting identified the PtxS operator sequence 50 bp upstream from the PtxR sites. EMSA demonstrated binding of PtxS to the gad, kgu and ptxS promoters. PtoxA::lacZ and Pkgu::lacZ transcriptional fusions using a ptxS knockout mutant demonstrated anti-activation by PtxS of PtxR’s functions, validating the role of PtxS as anti-activator.
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|
|TGAAACCGGTTTCA||ptxS, PA2260, PA2261, PA2262, PA2263,||
|TGAAACGTTTTTTC||PA2264, PA2265, PA2266||