Figure 4.

Measurement of apparent dissociation constants ($K_{{\text{d}}_{\text{app}}}$) between purified zinc finger proteins and their predicted target DNA sequences. $K_{{\text{d}}_{\text{app}}}$ values were estimated as described previously (24) with the exceptions that assays were performed in HE™ microplates (Molecular Devices, Sunnyvale, CA) and that microplates were washed using a Multiwash Advantage (Tri Continent, Grass Valley, CA) plate washer. Zinc finger proteins and corresponding DNA sequences were: (A) WNK with 5′-TCC-3′; (B) WRR with 5′-GCA-3′; (C_i) TPR and (C_ii) WPR, both with 5′-GTT-3′; (D) RTC with 5′-ACG-3′; and (E) TYR with 5′-TAC-3′, where letters represent the amino acids at positions −1, 3 and 6 in the α-helix in the second zinc finger of protein ZFH (30). All experiments were performed in quadruplicate. Error bars represent 1 SD.