Figure 2.

Structure of the influenza virus RNA polymerase. (A) Surface presentation of the influenza A virus RNA polymerase (PDB 6RR7) bound to capped RNA primer and 5′ and 3′ vRNA termini. The subunits of the RNA polymerase are colored as in Figure 1. (B) Schematic model of the influenza A virus RNA polymerase showing the core chamber of the polymerase and its connection to the solvent via template and nucleotide triphosphate (NTP) entry channels, and template and product exit channels. The location of the priming loop (PL) as well as the 3′ and 5′ end-binding pockets are indicated.