Glycerol-3-phosphate (aka 3-phospho-D-glycerate, 3PG) is a metabolic intermediate of glucose, lipid and energy metabolism. Its cellular levels may be regulated by cytosolic glycerol-3-phosphate phosphatase (PGP aka G3PP), which hydrolyses 3PG to glycerol. PGP functions as a homodimer, binding one Mg2+ ion per subunit. The function of the human protein is inferred from rat Pgp characterisation and functional studies (Mugabo et al. 2016).