The ligand binding domain (LBD) of the Ecdysone receptor, a member of the nuclear receptors super family
The ligand binding domain (LBD) of the ecdysone receptor: The ecdysone receptor (EcR) belongs to the superfamily of nuclear receptors (NRs) of ligand-dependent transcription factors. Ecdysone receptor is present only in invertebrates and regulates the expression of a large number of genes during development and reproduction. ECR functions as a heterodimer by partnering with ultraspiracle protein (USP), the ortholog of the vertebrate retinoid X receptor (RXR). The natural ligands of ecdysone receptor are ecdysteroids#the endogenous steroidal hormones found in invertebrates. In addition, insecticide bisacylhydrazine used against pests has shown to act on EcR. EcR must be dimerised with a USP for high-affinity ligand binding to occur. The ligand binding triggers a conformational change in the C-terminal part of the EcR ligand-binding domain that leads to transcriptional activation of genes controlled by EcR. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, ec dysone receptors have a central well conserved DNA binding domain (DBD), a variable N-terminal domain, a non-conserved hinge and a C-terminal ligand binding domain (LBD).