GPER is a G protein-coupled seven-transmembrane receptor. It is believed that the N-terminus is located outside of the cell, and that aspartic acid residues in the terminal region might be modified by glycosylation if GPER is localized in the plasma membrane. It is speculated that the ligand associates with the N-terminal domain to activate the receptor. Trimeric G protein is presumed to bind to the 3rd loop of the intracellular domain based on the molecular structure. A PDZ domain appears to be in the C-terminal region of GPER, but its physiological role is unknown.