Figure 2.

ELISA analysis of zinc finger DNA-binding specificities. The indicated three-finger proteins (A) and six-finger proteins (B) were expressed in E. coli as MBP fusion proteins. Specificity of binding was analyzed by measuring the binding activity in total lysates to immobilized biotinylated hairpin oligonucleotides containing the indicated 9-bp (A) or 18-bp (B) targets. The nucleotide sequences of the six-finger nontarget oligonucleotides were as follows: e1a, 5′-GCC GAG GCG GCC GGA GTC-3′; e1b, 5′-GTT GTG GCG TTG GCG GCG-3′; b3, 5′-GCC TGA GAG GGA GCG GTG-3′; c5, 5′-GCG GAG GCA GGA GGC GGG-3′; zif-zif, 5′-GCG TGG GCG GCG TGG GCG-3′ (B). Assays were performed in duplicate and the maximal signals were normalized to 1. The open box on top of each bar represents the standard deviation.