Identification of the interaction between pUL23 and pUL85. A) pUL23 interacts with pUL85 in a yeast two-hybrid assay. Yeast clones grown on selective plates and formation of blue colour in filter paper containing X-gal indicate protein-protein interaction between full-length pUL23 and pUL85; B) GST protein or GST-fusion proteins of pUL85 bound to glutathion-Sepharose bead were incubated with lysates prepared from cos7 cells transfected pcDNA3.1(+)-UL23-Flag. Bound proteins were analyzed by western blot (WB) with anti-Flag Antibody; C) Identificaiton of the interaction between pUL23 with pUL85 by co-immunoprecipitation (Co-IP) analysis. Cos-7 cell were transiently transfected with vectors expressing both Flag-tagged-pUL23 and HA-tagged-pUL85 fusion proteins (co-transfected) or with either vector alone, lysed, and subjected to immunoprecipitation with anti-Flag antibody. The immunoprecipitated material was electrophoresed and detected with anti-Flag and anti-HA antibody, respectively