EMSA analysis. (A) Sequence-specific DNA binding of Al–HD and Cll–N3C3. In all, 10 pmol of Al–HD, 20 pmol of Cll–N3C3, and 2 pmol of FITC-labelled dsDNA were used for each binding reaction. (B) Cooperative DNA binding of Al–HD and Cll–N3C3. The following Al and Cll constructs were added to each binding reaction—lane 1: no protein; lanes 2, 3, and 4: 1.25, 2.50, and 5.00 pmol of Al–HD, respectively; lanes 5, 6, and 7: 1.25, 2.50, and 5.00 pmol of Al–HD, respectively, and 260 pmol of Cll–N3C3; lanes 8, 9, and 10: 16.3, 32.6, 65.2 pmol of Cll–N3C3, respectively; lanes 11, 12, and 13: 16.3, 32.6, 65.2 pmol of Cll–N3C3, respectively, and 100 pmol of Al–HD. Each binding reaction contains 2 pmol of FITC-labelled dsDNA. (C) Cooperative DNA-binding affinities of Cll constructs (Cll–N3C3, Cll–N3C2, Cll–N2C3, Cll–N2C2, Cll–N1C2, and Cll–N2C1) with Al–HD. In all, 10 pmol of Al–HD, 20 pmol of Cll constructs, and 2 pmol of FITC-labelled dsDNA were used for each binding reaction. (D) Binding affinities (KDs) of the indicated proteins. (E) Summary of the EMSA analysis. The N2–C2 region is required for the cooperative DNA binding with Al–HD.