Helix-turn-helix, HxlR type (IPR002577)

Short name: HTH_HxlR

Overlapping homologous superfamilies

Domain relationships



The hxlR-type HTH domain is a domain of ~90-100 amino acids present in putative transcription regulators with a winged helix-turn-helix (wHTH) structure. The domain is named after Bacillus subtilis hxlR, a transcription activator of the hxlAB operon involved in the detoxification of formaldehyde [PMID: 10572115]. The hxlR-type domain forms the core of putative transcription regulators and of hypothetical proteins occurring in eubacteria as well as in archaea. The sequence and structure of hxlR-type proteins show similarities with the marR-type wHTH [PMID: 11839496].

The crystal structure of ytfH resembles the DNA-binding domains of winged helix proteins, containing a three helix (H) bundle and a three-stranded antiparallel beta-sheet (B) in the topology: H1-H2-B1-H3-H4-B2-B3-H5-H6. This topology corresponds with that of the marR-type DNA-binding domain, wherein helices 3 and 4 comprise the helix-turn-helix motif and the beta-sheet is called the wing.

Contributing signatures

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