In addition, these proteins are involved in the formation of E3 ubiquitin-protein ligase complex with cullin 5, Ring-box 1, and elongins B and C. E1B-55k and E4orf6 inhibit PKR and eIF2α phosphorylation at late stages of infection in a cullin 5-dependent manner, suggesting that these proteins may act by triggering PKR degradation. Here, CUL5 is linked to infection.