Located in the inner capsid layer linked to the dsRNA core, VP1, VP2, and VP3 along with other NSPs play a key role in viral transcription. Specically, being an RNA polymerase enzyme, VP1 is responsible for producing mRNA transcripts for the synthesis of viral proteins and for replicating the rotavirus genome RNA segments for new virus particles inside the infected host cells. VP2 binds the RNA genome; and VP3 is a guanylyl transferase that catalyses the formation of the 5′ cap in the post-transcriptional modication of mRNA. This
process stabilizes viral mRNA by protecting it from nucleases of the host cell.