Liver X receptor beta (LXR-ò) is a member of the nuclear receptor family of transcription factors. LXR-ò is encoded by the gene (nuclear receptor subfamily 1, group H, member 2).
The liver X receptors (LXRs) were originally identified as orphan members of the nuclear receptor superfamily because their ligands were unknown. Like other receptors in the family, LXRs heterodimerize with retinoid X receptor and bind to specific response elements (LXREs) characterized by direct repeats separated by 4 nucleotides. Two genes, alpha (LXRA) and beta, are known to encode LXR proteins.
Crystal structure of human liver X receptor ò(LXRò) forming heterodimer with its partner retinoid X receptor ñ(RXRñ) on its cognate element, an AGGTCA direct repeat spaced by 4 nt shows an extended X-shaped arrangement, with DNA- and ligand-binding domains crossed. The LXRò core binds DNA via canonical contacts and auxiliary DNA contacts that enhance affinity for the response element.
Liver X receptor beta has been shown to interact with NCOA6 and Retinoid X receptor alpha.