DNA binding motifs

It is composed of two alpha helices joined by a short strand of amino acids and is found in many proteins that regulate gene expression.


Zinc fingers are small protein structural motifs that can coordinate one or more zinc ions to help stabilize their folds. They can be classified into several different structural families (zinc finger proteins) and typically function as interaction modules that bind DNA, RNA, proteins, or small molecules.


This motif is usually found as part of a DNA-binding domain in various transcription factors, and is involved in regulating gene expression. Leucine zippers are found in both eukaryotic and prokaryotic regulatory proteins, but are mainly a feature of eukaryotes. The leucine zipper is a super-secondary structure that functions as a dimerization domain, and its presence generates adhesion forces in parallel alpha helices. A single leucine zipper consists of multiple leucine residues at approximately 7-residue intervals, which forms an amphipathic alpha helix with a hydrophobic region running along one side. This hydrophobic region provides an area for dimerization, allowing the motifs to "zip" together. Furthermore, the hydrophobic leucine region is absolutely required for DNA binding.