Phosphate-binding protein (PstS) (PstS)

The Phosphate-specific transport protein, primarily known as PstS, is the substrate-binding component of the high-affinity phosphate-specific transport (Pst) system in bacteria [1, 2]. It functions by capturing inorganic phosphate in the periplasmic space or on the cell surface and delivering it to the PstABC ABC transporter complex for translocation into the cytoplasm [5, 24]. This system is essential for bacterial survival under phosphate-limiting conditions, which are often encountered within the host environment during infection [1, 3]. In pathogens like Mycobacterium tuberculosis, the PstS1 protein is a major immunodominant antigen and plays a critical role in virulence, phosphate sensing, and host cell adhesion [2, 6]. PstS has emerged as a significant therapeutic target for the development of diagnostic tools, such as nanobody-based imaging for tuberculosis, and prophylactic interventions, including next-generation mRNA vaccines targeting multidrug-resistant Enterobacteriaceae [6, 18]. Experimental inhibitors and vaccines targeting this protein aim to disrupt bacterial nutrient acquisition and reduce fitness, thereby providing a novel strategy to combat antimicrobial resistance [12, 18].

Other names

Phosphate-specific transport proteinPstS138 kDa antigenPeriplasmic phosphate-binding proteinPhosphate-specific transport system periplasmic binding proteinAntigen 5

Induction of protective immune responses through vaccination; diagnostic binding for molecular imaging of infection sites; potential inhibition of high-affinity phosphate uptake to impair bacterial survival and virulence.