Helix-turn-helix motifs

From Biology-Online Dictionary
Jump to: navigation, search

Helix-turn-helix motifs

The first DNA-binding protein motif to be recognised. Helix-turn-helix motifs were originally identified in bacterial proteins but have since been found in hundreds of DNA-binding proteins from both eukaryotes and prokaryotes. They are constructed from two alpha helices connected by a short extended chain of amino acids, which constitute the turn. the two helices are held at a fixed angle, primarily through interactions between the two helices.