Interaction of TAND with TBP mutants. His-tagged TBP mutants (300 nM), as indicated below each panel, were incubated with glutathione resin containing a 300 nM concentration of either GST-yTAND(10-88) (wild type [WT]), GST-TAND(D66K), or GST-TAND(F23K D66K). Resins were washed, and proteins were eluted and analyzed by SDS-PAGE. TBP was detected by immunoblotting with polyclonal antibodies directed against TBP. The GST-TAND derivatives were detected with GST antibodies. The GST-TAND signal is not comparable between panels, since different lots of GST antibodies were used for some. Shown in each panel is 10% of the input. Mutants not shown here are presented in reference 24.