EMSA determined P. aeruginosa contains a protein that specifically binds to the ptxS upstream region. A P. aeruginosa PAO1::ptxS mutant was constructed, identifying PtxS as the ptxS binding protein. EMSA using PtxS expressed from the T7 promoter in E.coli K38 demonstrated specific PtxS binding to the ptxS upstream region. A ptxS::lacZ fusion was utilized, showing beta gal activity four- to five times higher in the ptxS knockout mutant, confirming PtxS as an auto-regulator. DNase I footprinting isolated the specific sequence for PtxS 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|