Probable oocyte-specific oolemmal receptor involved in sperm and egg adhesion and fertilization. May act as a protease (By similarity). Binds 1 zinc ion per subunit. Expressed in ovary and gonads. Expressed in embryonic stem cells. Expressed in the pluripotent cells of the epiblast. Detected at the junction of non-neuronal and neuronal ectoderm just before neural tube closure. Expressed in the ventral epidermis before ventral closure, in the intermediate mesoderm, gonads and the forming nephric duct and tubules of the mesonephros and metanephros.