Member of the two-component regulatory system GtrS/GltR involved in the regulation of glucose metabolism and transport, as well as regulation of the exotoxin A gene expression (PubMed:24920832). GtrS recognizes and binds 2-ketogluconate and 6-phosphogluconate via its sensor domain, which accelerates GtrS autophosphorylation and concomitant transphosphorylation and regulation of the response regulator GltR (PubMed:24920832). Plays a key role during bacteria-host interactions and is required for optimal colonization and dissemination in a mouse model of infection (PubMed:22262100). Contributes to modulation of the type III secretion system (T3SS) in response to host cells via the regulation of the OprB transport system (PubMed:22262100). ATP + protein L-histidine = ADP + protein N-phospho-L-histidine. Induced during infection of airway epithelial cells. Autophosphorylated. Inactivation of the gene results in elevated ingestion and reduced cytotoxicity of eukaryotic cells during P.aeruginosa infection.