Coimmunoprecipitation of independently expressed N- and C-terminal domains of UL16. Plasmids encoding NT or CT (or their derivatives) were transfected into Vero cells either alone or together, as indicated. At 16 to 20 h posttransfection, cell lysates were prepared, and these were either analyzed by immunoblotting to measure the input expression levels (A, D, and F) or incubated with the antibodies shown at the tops of the lanes to collect interacting complexes, which were then analyzed by immunoblotting (B, C, E, and G). The antibody used for immunoblotting is indicated at the bottom left of each panel.