This family the N-terminal region of the Betacoronavirus polyprotein which contains non-structural protein 1 (Nsp1) from Betacoronavirus lineage A. This protein is important for viral replication and pathogenesis. It suppresses the host innate immune functions by inhibiting type I interferon expression and host antiviral signalling pathways.
Jiyao W et al.(2023). "The conserved domain database in 2023.",