Arabinose metabolism transcriptional repressor, ligand-binding domain (IPR033532)

Short name: AraR_ligand_bind_dom

Overlapping homologous superfamilies

Domain relationships



This entry represents the ligand-binding domain of AraR, which is a member of the LacI-GalR family of bacterial transcription regulators. It is involved in L-arabinose-inducible expression of the araABDLMNPQ-abfA metabolic operon and of the araE/araR genes that are organized as a divergent transcriptional unit in Bacillus subtilis [PMID: 10417639].

The ligand-binding domain of AraR is structurally homologous to the periplasmic sugar-binding domain of ABC-type transporters and both domains contain the type I periplasmic binding protein-like fold. The LacI-GalR family repressors are composed of two functional domains: an N-terminal HTH (helix-turn-helix) domain, which is responsible for the DNA-binding specificity, and a C-terminal ligand-binding domain, which is homologous to the type I periplasmic binding proteins. As also observed in the periplasmic binding proteins, the C-terminal domain of the bacterial transcription repressor undergoes a conformational change upon ligand binding which in turn changes the DNA binding affinity of the repressor [PMID: 16585763].

GO terms

Biological Process

GO:0006355 regulation of transcription, DNA-templated

Molecular Function

No terms assigned in this category.

Cellular Component

No terms assigned in this category.

Contributing signatures

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