Outer membrane porin PhoE (PhoE) (PhoE)

Bacterial outer membrane porin PhoE, also known as phosphoporin, is a trimeric transmembrane protein found in the outer membrane of Gram-negative bacteria like Escherichia coli and Klebsiella pneumoniae [1.2.1, 1.2.2]. It functions as a general diffusion pore with a high selectivity for anions, specifically facilitating the uptake of inorganic phosphate and phosphorylated compounds during periods of phosphate starvation [1.1.3, 1.2.1]. PhoE is a critical component of the bacterial stress response, regulated by the Pho regulon to ensure nutrient acquisition in nutrient-poor environments [1.2.1, 1.3.5]. In medicine, PhoE is a major entry point for various hydrophilic antibiotics, including beta-lactams, fluoroquinolones, and tetracyclines, making it essential for drug efficacy [1.3.1, 1.4.1]. However, bacteria often develop resistance by downregulating PhoE expression or through mutations that constrict the pore, thereby limiting antibiotic influx [1.3.3, 1.4.2]. Additionally, PhoE is a target for vaccine research due to its surface-exposed loops and strong immunogenic properties [1.3.3, 1.4.5]. It also serves as a binding site for host defense molecules such as lactoferrin, which can inhibit bacterial growth by interacting with the porin [1.2.3]. Understanding the structural dynamics of PhoE is vital for developing next-generation antimicrobials that can bypass or exploit this transport system [1.3.2, 1.4.3].

Other names

PhosphoporinOuter membrane pore protein EPhosphate-selective porin

Facilitates the translocation of hydrophilic antibiotics across the bacterial outer membrane and serves as an antigenic target for vaccine-induced immunity.