Transcriptional activation of the human interferon-beta (IFN-beta) gene by virus infection requires the assembly of a higher order nucleoprotein complex, the enhanceosome, which consists of the transcriptional activators NF-kappa B (p50/p65), ATF-2/c-jun, IRF-3 and IRF-7, architectural protein HMGI(Y), and the coactivators p300 and CBP.