(A) GST-TbENF interacting proteins were captured through incubation with procyclic T. brucei whole cell extract and the interactions were challenged with up to 0.9 M KCl washes (three 5 minute washes at room temperature). Interacting proteins were queried through Western blot. Using antibodies against TbTFIIB, TbRNAPII, and TbTBP, it was found that GST-TbENF interacts tightly with TbTFIIB (top panels), but not with TbRNAPII or TbTBP (bottom panels) under these conditions. (B) As a control, the GST-TbENF TbTFIIB interaction studies were carried out with T. brucei whole cell extract treated with DNase.