Figure 2.

Adenovirus type 9 (Ad9) E4 region-encoded open reading frame 1 (E4-ORF1) consists of two protein-interaction elements, designated domain 2 (D2) and PDZ domain-binding motif (PBM). Centrally located D2 and the carboxyl-terminal PBM are defined by mutants G40V, V41A, D65A, L89Q, F91S, H93A and F97A or mutants IIIA, T123D and V125A, respectively. CrucialD2 residues (bracketed numbers) and crucial PBM residues (italicized) are shown. Cellular targets that bind D2 or PBM are also indicated. The E4-ORF1 trimerization (TRI) element overlaps the PBM sequence.