Disease relevance of ptxS

• The Pseudomonas aeruginosa global regulator MvaT specifically binds to the ptxS upstream region and enhances ptxS expression [1].
• In addition, the gel shift band was detected when the 52-bp fragment was incubated with a lysate of Escherichia coli in which ptxS was overexpressed from the T7 promoter [2].

High impact information on ptxS

• Furthermore, a plasmid carrying a fragment that contains ptxS and ORFs 1-4 complemented the defect of the previously described P. aeruginosa 2-ketogluconate-negative mutant [3].
• Similarly, a previously constructed ptxS isogenic mutant of PAO1 did not grow in a minimal medium containing 2-ketogluconate as the sole carbon source [3].
• These results suggest that: (i) ptxS together with the other four ORFs constitute the 2-ketogluconate utilization operon (kgu) in P. aeruginosa [3].
• Autoregulation of the Pseudomonas aeruginosa protein PtxS occurs through a specific operator site within the ptxS upstream region [4].
• In the initial analysis, different-sized gel shift bands were detected when a probe containing the ptxR-ptxS intergenic region was incubated with the lysate of P. aeruginosa PAO1 [2].

Chemical compound and disease context of ptxS

• The Pseudomonas aeruginosa exotoxin A regulatory gene, ptxS: evidence for negative autoregulation [2].

Biological context of ptxS

• Our results also indicate that negative regulation of ptxR expression by PtxS does not occur through the PtxS binding site within the ptxR-ptxS intergenic region [5].
• Nucleotide sequence analysis of the 2.1-kbp fragment at the 5' end of ptxR revealed the presence of an open reading frame designated ptxS (the gene next to ptxR) which encodes a 37.4-kDa protein [6].
• The deduced amino acid sequence of ptxS exhibited a strong homology to several proteins of the GalR-LacI family of repressors [6].

Associations of ptxS with chemical compounds

• We have also described another gene, ptxS, which is transcribed divergently from ptxR and interferes with the enhancement of exotoxin A synthesis by ptxR [2].

Regulatory relationships of ptxS

• These results suggest that ptxS encodes a protein which negatively regulates ptxR expression in P. aeruginosa [6].

Other interactions of ptxS

• Recombinant MvaT was purified as a fusion protein (MAL-MvaT) and shown to specifically bind to the ptxR-ptxS intergenic region [1].

Analytical, diagnostic and therapeutic context of ptxS

• In this study, we used site-directed mutagenesis and promoter fusion experiments to determine if PtxS binds specifically to this palindromic sequence and regulates ptxS expression [4].
• Additional Northern blot hybridization experiments confirmed that ptxS is transcribed in P. putida and P. fluorescens strains that carried no plasmid [7].

References