Poliovirus type 1 capsid protein VP1 (VP1)

The poliovirus type 1 capsid protein VP1 is one of four structural proteins (VP1, VP2, VP3, VP4) that form the icosahedral capsid enclosing the viral RNA genome, with 60 copies of each protein arranged symmetrically. VP1 features an eight-stranded β-barrel core decorated with loops and extensions that contribute to the capsid's corrugated surface, including the "canyon" surrounding fivefold axes where the host receptor (PVR/CD155) binds via VP1's floor and rims. This interaction triggers irreversible conformational changes to the 135S "A-particle" intermediate, externalizing VP4 and VP1's N-terminal amphipathic helix to facilitate membrane attachment and RNA translocation during infection. VP1 also houses a hydrophobic pocket at the canyon base, often occupied by a "pocket factor" that stabilizes the virion. In poliovirus infection, VP1 enables epithelial cell entry, replication, and pathogenesis, historically linked to poliomyelitis. Although not a human protein target, VP1 is exploited in vaccine design (e.g., inactivated polio vaccine) and studied for antiviral pocket-binding inhibitors, though no approved small-molecule drugs directly target it.

Other names

Poliovirus capsid protein VP1VP1 protein