Influenza A virus polymerase basic protein 2 subunit (PB2)

The **Influenza A virus polymerase basic protein 2 subunit (PB2)** is one of three essential subunits (with PA and PB1) of the heterotrimeric influenza A RNA-dependent RNA polymerase complex. PB2 is responsible for binding capped RNA fragments stolen from host mRNAs—a critical process called "cap-snatching"—to prime synthesis of viral mRNA[2][3][7]. PB2's cap-binding domain is a validated antiviral target; mutations (notably at residue 627) are key determinants of host range and pathogenicity, influencing the virus's capacity to infect different species and its virulence. As part of the viral replication machinery, PB2 is indispensable for viral transcription and replication in infected host cells and is a major focus of drug development and surveillance for influenza pandemic preparedness[1][2][3][4][7].

Other names

Polymerase basic protein 2PB2 subunitInfluenza virus PB2 protein

Inhibition of PB2 prevents proper cap-binding and "cap-snatching," blocking viral mRNA synthesis and replication[2][3][7]. Some compounds block the RNA-protein interaction or cap recognition, preventing viral transcription.