Helix-turn-helix motif

The helix-turn-helix motif is a common structural pattern in proteins that allows them to bind to specific DNA sequences. It consists of two helical regions (alpha helices) connected by a short flexible segment called the turn. The first helix helps recognize and attach to the DNA, while the second helix stabilizes this interaction. This design enables the protein to precisely control gene activity by physically interacting with DNA. The helix-turn-helix motif is found in many gene-regulating proteins across different organisms, playing a crucial role in turning genes on or off.