Catalytic component of the DNA-directed RNA polymerase (RNAP) that catalyzes the transcription in the cytoplasm of viral DNA into RNA using the four ribonucleoside triphosphates as substrates (By similarity). Forms the polymerase active center together with RPB1 (By similarity). Part of the core element with the central large cleft, the clamp element that moves to open and close the cleft and the jaws that are thought to grab the incoming DNA template (By similarity). a ribonucleoside 5'-triphosphate + RNA(n) = diphosphate + RNA(n+1) Part of the viral DNA-directed RNA polymerase that consists of 8 polII-like subunits (RPB1, RPB2, RPB3, RPB5, RPB6, RPB7, RPB9, RPB10), a capping enzyme and a termination factor. Found in association with viral nucleoid. Expressed in the late phase of the viral replicative cycle. The binding of ribonucleoside triphosphate to the RNA polymerase transcribing complex probably involves a two-step mechanism. The initial binding seems to occur at the entry (E) site and involves a magnesium ion coordinated by three conserved aspartate residues of the two largest RNA Pol subunits. Belongs to the RNA polymerase beta chain family.