PilY1 protein (PilY1)

PilY1 is a large (~126 kDa) non-pilin protein involved in the assembly and function of type IV pili in various bacteria, prominently Pseudomonas aeruginosa. It serves as a tip-associated adhesin, facilitating bacterial adhesion to surfaces, host cells, and substrates, thereby enabling colonization and biofilm formation. PilY1 is composed of a von Willebrand factor type A (vWA) domain at the N-terminus, associated with mechanosensing and adhesion, and a C-terminal seven-bladed β-propeller fold that binds calcium via an EF-hand-like motif, critical for regulating cycles of pilus extension and retraction. PilY1 interacts with the secretin PilQ and the minor pilin complex to optimize pilus architecture, integrating both mechanical and chemical signals for surface engagement and motility. The protein is evolutionarily related to Neisseria PilC and is conserved among pathogenic bacteria with retractile type IV pili. Absence or mutation of PilY1 disrupts pilus formation, bacterial motility, and virulence, making it a potential focus of antibacterial research.

Other names

PilY1Type IV pilus biogenesis factor PilY1Non-pilin pilus tip adhesinNeisseria-PilC superfamily protein