H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate Binds 2 magnesium ions per subunit. Belongs to the PP2C family. Although related to the protein phosphatase 2C family, lacks 1 of the conserved residues that bind manganese, suggesting it has no phosphatase activity. Could be the product of a pseudogene.