Protein that inhibits host translation while promoting late viral translation by ribosome shunting. Blocks host cap-dependent translation by binding to eIF4G, displacing MKNK1 from cap initiation complexes and preventing EIF4E phosphorylation. Binds to the tripartite leader sequence of viral late mRNAs and recruits host eIF4G, PABPC1/poly-A binding protein and 40S ribosomes subunits on viral mRNAs, allowing ribosome shunting and efficient translation of late viral mRNAs even though conventional translation via ribosome scanning from the cap has been shut off in the host cell. During assembly, acts as a chaperone protein that helps hexon proteins assembly into trimers