FIG. 4.

Comparison of the effect of ICP4 and Gal4-VP16 on the recruitment of HA-TFIID to immobilized promoters. HA-TFIID (4 μl) was incubated with 100 fmol of immobilized G₅E4T or gC promoter templates in the presence of 75 to 300 fmol of purified ICP4 (approximately 25 to 100 ng) on in the absence of ICP4 or with 300 to 2,400 fmol of purified Gal4-VP16 (approximately 7.5 to 60 ng) in a total volume of 300 μl. As a control for the DNA binding specificity of the Gal4-VP16 protein, this protein (at the highest concentration used only) was incubated with HA-TFIID and immobilized gC promoters (lane 13). After incubation at 30°C, nucleoprotein complexes bound to immobilized promoters were isolated and analyzed as described in Materials and Methods.