Figure 1.

(a) Schema of a C2H2 zinc finger motif: C2H2-type zinc finger contains a short beta hairpin and an alpha helix (beta/beta/alpha structure), where a single zinc atom is held in place by Cys(2)His(2) (C2H2) residues in a tetrahedral array. (b) Amino acid sequences of exons 8 and 9: the sequence-recognition amino acids at the protein-DNA interface in exons 8 and 9 (in yellow). The Cys2-His2 structural amino acids that coordinate the zinc ions and hydrophobic core are shown in red letters. C2H2, zinc finger structure formed by 2 cysteines and 2 histidines.