FIG. 8.
CBP-binding-domain mutants of Tax are defective for 4° but not 3° complex formation in vitro. (A) SDS-PAGE (12% gel) analysis of purified wild-type (WT) and mutant Tax proteins (marked by an arrow). Proteins were stained with Coomassie blue. Lane M., size markers. (B) EMSA analysis of wild-type and mutant Tax proteins in the presence or absence of GST-CBP451-682. Nucleoprotein complexes are indicated on the right. (C) The L90A protein displayed no defect in its interaction with GST-CBP451-682 or GST-CREB bZip compared to wild-type Tax.