Figure 3.

Amino acid sequence alignment of six-finger proteins specific for the 18-bp target sequence e2c. Recognition helix positions −2 to 6 of each finger (F1 to F6) are underlain with dark gray boxes and labeled according to their DNA-binding specificity. Sequence identities in the framework regions are underlain with light gray boxes. Positions of the conserved cysteine and histidine residues are marked by asterisks. The corresponding positions of the SfiI recognition sites, used for cloning the zinc finger coding regions into the various expression vectors, as well as the BsrF1 and XmaI recognition sites, used for the construction of DNAs encoding six-finger proteins, are indicated.