Leucine zipper Recognition helices DNA GNⅫN (b) 2012 Pearson Education.Inc Eukaryotic DNA binding proteins substructures. (b)The leucine zipper structure亮氨酸拉链结构.The leucine residues(shown in yellow)are always spaced exactly every seven amino acids.Eukaryotic DNA binding proteins substructures. (b) The leucine zipper structure亮氨酸拉链结构. The leucine residues (shown in yellow) are always spaced exactly every seven amino acids