Unprecedented conformational flexibility revealed in the ligand-binding domains of the Bovicola ovis ecdysone receptor (EcR) and ultraspiracle (USP) subunits

The crystal structure of the heterodimeric ligand-binding domains of the B. ovis ecdysone receptor was solved in the presence of an ecdysteroid and a synthetic methylene lactam insecticide, respectively. Analysis of these structures reveals a new level of conformational flexibility for the ecdysone receptor upon binding of ligands.