Strategy for screening of DNA-binding sequence for AML1, AML1-ETO, and AML1-ETOtr. (A) Schematic representation of HA-tagged proteins used for the screening of DNA-binding sequence. The Runt homology domain is indicated with a black box and 4 Nervy homology regions (NHRs) are shown as gray boxes. The predicted zinc finger motif in the C-terminal region of AML1-ETO is indicated with ▴. (B) The expression of AML1 (A), AML1-ETO (AE), and AML1-ETOtr (tr) in cell lysates was examined by immunoblotting with anti-HA antibody. Control (C) is the lysates from vector-transfected cells. (C) Target DNA sequence including 25N random sequence. indicate the position of forward or reverse primers for PCR amplification, and boxes show the position of restriction enzyme digestion sites for subcloning.