Curation Information

The Pseudomonas aeruginosa exotoxin A regulatory gene, ptxS: evidence for negative autoregulation.;Swanson BL, Colmer JA, Hamood AN;Journal of bacteriology 1999 Aug; 181(16):4890-5 [10438759]
PtxS [G3XD97, view regulon]
Reported TF sp.
Pseudomonas aeruginosa PAO1
Reported site sp.
Pseudomonas aeruginosa PAO1
Created by
Grace Chandler
Curation notes

Experimental Process

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.

Transcription Factor Binding Sites


Gene Regulation

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