Protein Motifs: the Helix-Turn-Helix Motif
Published Online: 28 SEP 2007
Copyright © 2001 John Wiley & Sons, Ltd. All rights reserved.
How to Cite
Matthews, B. W. 2007. Protein Motifs: the Helix-Turn-Helix Motif. eLS. .
- Published Online: 28 SEP 2007
The helix-turn-helix motif was first observed in the structures of certain proteins that bind to specific regulatory sites on deoxyribonucleic acid (DNA). It is made up of a part of the protein comprising an α-helix followed by a turn followed by a second α-helix aligned approximately 120° to the first. When the protein binds to its regulatory site, the second α-helix of the helix-turn-helix occupies one of the grooves on the DNA and is critical in recognizing the correct target.
- DNA binding;
- gene regulation