Helix-turn-helix, type 11 (IPR013196)

Short name: HTH_11

Overlapping homologous superfamilies

Domain relationships



Winged helix DNA-binding proteins share a related winged helix-turn-helix DNA-binding motif, where the "wings", or loops, are small beta-sheets. The winged helix motif consists of two wings (W1, W2), three alpha helices (H1, H2, H3) and three beta-sheets (S1, S2, S3) arranged in the order H1-S1-H2-H3-S2-W1-S3-W2 [PMID: 10679470]. The DNA-recognition helix makes sequence-specific DNA contacts with the major groove of DNA, while the wings make different DNA contacts, often with the minor groove or the backbone of DNA. Several winged-helix proteins display an exposed patch of hydrophobic residues thought to mediate protein-protein interactions.

This entry represents a subset of the winged helix domain superfamily which is predominantly found in bacterial proteins, though there are also some archaeal and eukaryotic examples. This domain is commonly found in the biotin (vitamin H) repressor protein BirA which regulates transcription of the biotin operon [PMID: 1409631]. It is also found in other proteins including regulators of amino acid biosynthsis such as LysM [PMID: 12042311], and regulators of carbohydrate metabolisms such as LicR and FrvR [PMID: 10438772, PMID: 8019415].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.