Figure 1.

Illustration of different 7ZFP variants. (a) The 21 bp p16 promoter target sequence, including the Sp1-binding site (9 bp) and its 5′-flanking sequence (12 bp, underlined); The zinc-finger directly binding deoxynucleotides are marked with bold characters; (b) Motifs in the artificial 7ZFP construction and their binding deoxynucleotides; fingers in pink or blue frames derived from Sp1 finger-3 and finger-2, respectively; (c) Locations of different alterations in the 7ZFP variants (deep red bars and arrow).