Plays an important role in stimulating the translation of viral mRNAs. These mRNAs are capped but not polyadenylated, instead terminating in a conserved sequence 'GACC' at the 3' that is recognized by NSP3, which competes with host PABPC1 for EIF4G1 binding. The interaction between NSP3 and host EIF4G1 stabilizes the EIF4E-EIF4G1 interaction, thereby facilitating the initiation of capped mRNA translation. Homodimer. Interacts (via the coiled-coil region) with host ZC3H7B (via LD motif). Interacts with host EIF4G1. Belongs to the rotavirus NSP3 family.