FIG. 6.

(A) Tax and SRC-1 binding to CR2_{aa2003–2212} is mutually exclusive. SRC-1 [³⁵S]-labeled transcription-translation product (0.1 μl) was incubated with GST alone or GST-CR2_{aa2003–2212} (5 pmol) (lanes 4 and 9 to 15) in the presence of increasing amounts of wild-type Tax protein (5, 50, and 100 pmol) (lanes 10 to 12) or Tax Y312→E (5, 50, and 100 pmol) (lanes 13 to 16). Wild-type (wt) and Y312→E Tax (50 pmol) were also incubated with GST alone (5 pmol) (lanes 5 and 6) or GST-CR2_{aa2003–2212} (5 pmol) (lanes 7 and 8). Bound proteins were separated by SDS–12% PAGE. Top, PhosphorImager analysis of bound SRC-1. Bottom, Western blot analysis using anti-His₆ antibody. The positions of SRC-1 onput (100%) (lane 1), wild-type Tax (5 pmol) (lane 2), and Tax Y312→E (5 pmol) (lane 3) and molecular size markers are indicated (in kilodaltons).