Figure 2.

Purification of GST-EBNA2-associated HAT activity. BJAB cell extracts were incubated with GST-EBNA2 beads. The HAT activity was eluted from the beads with 0.2 M NaCl and loaded onto 10–30% sucrose gradient. Fractions containing HAT activity were pooled, applied to anion-exchange column, and eluted with a linear 50- to 300-mM NaCl gradient. Protein fractions from sucrose gradient (A) and UNO Q column (B) were separated by SDS/PAGE and identified by Western blot with anti-CBP/p300 antibody (Lower). The HAT activity of these fractions also was measured (Upper) and shown in 10⁴ × count per minute. Fraction numbers are indicated just below the Upper parts of A and B.