Influenza viral RNA-dependent RNA polymerase (RdRp)

The influenza viral RNA-dependent RNA polymerase (RdRp) is a heterotrimeric enzyme complex essential for the replication and transcription of the influenza virus genome. It is composed of three distinct subunits: polymerase acidic (PA), polymerase basic 1 (PB1), and polymerase basic 2 (PB2), which together form a functional unit within the viral ribonucleoprotein (vRNP) complex. The RdRp is responsible for synthesizing both messenger RNA (mRNA) for viral protein production and genomic RNA (vRNA) for the assembly of new virions. A hallmark of its function is the "cap-snatching" mechanism, where the PB2 subunit binds host pre-mRNAs and the PA subunit cleaves them to provide primers for viral transcription. Due to its indispensable role in the viral life cycle and high conservation across different influenza strains, the RdRp is a major target for antiviral therapy. Drugs such as baloxavir marboxil and favipiravir specifically inhibit different subunits of this complex to halt viral proliferation.

Other names

Influenza virus RNA polymerase complexFluPolPA-PB1-PB2 complexInfluenza RNA replicaseInfluenza transcriptase