FIG. 5.

The C-terminal domain of Tax is involved in the specificity of ternary complex formation. (A) Detection of the mutants Tax 1-307 and M47 by Western blotting by using anti-histidine antibodies. Each of the Tax proteins was analyzed by Western blotting with anti-Tax or anti-histidine antibodies. (B) An amount of 100 ng of biotinylated TxRE III was incubated with 20 ng of CREB-2 in the absence (−) or the presence of 25 ng of either WT Tax (WT), mutant Tax 1-307, or Tax M47. The complexes were collected on streptavidin beads, and the proteins bound to the beads were analyzed by Western blotting with anti-CREB-2 (top panel) or anti-histidine (bottom panel) serum. The experiment was performed three times, with similar results.