Calcium-dependent, calmodulin-stimulated protein phosphatase. This subunit may have a role in the calmodulin activation of calcineurin. H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate Binds 1 Fe(3+) ion per subunit. Binds 1 zinc ion per subunit. Composed of two components (A and B), the A component is the catalytic subunit and the B component confers calcium sensitivity. Present with 7040 molecules/cell in log phase SD medium. Belongs to the PPP phosphatase family. PP-2B subfamily.