Structures of the orphan G-protein-coupled receptor GPR52 in ligand-free, G-protein-coupled and ligand-bound states reveal that extracellular loop 2 occupies the orthosteric binding pocket and functions as a built-in agonist to activate the receptor.
GPR52 is a class-A orphan G-protein-coupled receptor that is highly expressed in the brain and represents a promising therapeutic target for the treatment of Huntington'
