Figure 1.

CRSP binds to Ni²⁺-NTA-agarose column. (a) Sp1 activation requires CRSP in the 1 M phosphocellulose fraction (P1M). Transcription reactions contain Sp1 (lanes 1–3), RNA polymerase II and basal transcription factors (lanes 1–3), the P1M fraction (lane 2), and immunopurified TFIID (IP-TFIID) (lane 3). Transcription from a GC-box template and a control DNA template lacking Sp1 binding sites is indicated by filled and open arrowheads, respectively. (b) CRSP binds to Ni²⁺-NTA-agarose resin in the presence of competing imidazole. Transcription reactions were performed as described in a. The Ni²⁺-NTA-agarose flow-through (FT) fraction and eluate fractions under various binding conditions are tested (lanes 2–10). All Ni eluates are eluted with 100 mM imidazole. (c) CRSP elution profile. Transcription reactions were performed as described in a in the presence of input fraction (lane 1), flow-through fraction (lane 2), or eluate fractions under varying concentration of imidazole (lanes 3–13).