Norovirus GII.4 VP1 capsid protein (VP1)

The Norovirus GII.4 VP1 capsid protein is the major structural component of the GII.4 norovirus virion, a leading cause of viral gastroenteritis worldwide, forming 180 copies arranged in T=3 icosahedral symmetry with shell (S), protruding P1, and P2 domains. The S domain encases the positive-sense single-stranded RNA genome, while P domains create surface protrusions critical for flexibility, receptor binding to histo-blood group antigens (HBGAs) via P2 subdomain pockets, and host cell entry. GII.4 VP1 exhibits dynamic conformations, including "resting" and "rising" states influenced by divalent ions, enabling environmental stability and replication. Rapid evolution in the VP1 gene, especially under positive selection in shell and P domains, drives antigenic variants (e.g., Den Haag, Sydney) that evade immunity, sustaining epidemics over decades. This variability hinders vaccine efforts, as neutralizing antibodies target conserved yet mutable P2 sites, with no approved antiviral drugs directly interacting.

Other names

Major capsid proteinViral protein 1