Adenovirus E1B protein N-terminus
This family constitutes the amino termini of E1B 55 kDa (pfam01696). E1B 55K binds p53 the tumor suppressor protein converting it from a transcriptional activator which responds to damaged DNA in to an unregulated repressor of genes with a p53 binding site. This protects the virus against p53 induced host antiviral responses and prevents apoptosis as induced by the by the adenovirus E1A protein. The role of the N-terminus in the function of E1B is not known.