Binds estrogens with an affinity similar to that of ER-alpha, and activates expression of reporter genes containing estrogen response elements (ERE) in an estrogen-dependent manner. Binds DNA as a homodimer. Can form a heterodimer with ER-alpha (By similarity). A high expression is seen in the telencephalon, diencephalon, pituitary, testis and kidneys but little or no expression is seen in the cerebellum, pectoral muscle and adrenal gland. Composed of three domains: a modulating N-terminal domain, a DNA-binding domain and a C-terminal ligand-binding domain. Belongs to the nuclear hormone receptor family. NR3 subfamily.