Phosphoserine Phosphatase (PSPH)

Phosphoserine phosphatase is an enzyme belongs to a subfamily of the phosphotransferases. This encoded enzyme is responsible for the third and last step in L-serine formation. It catalyzes magnesium-dependent hydrolysis of L-phosphoserine and is also involved in an exchange reaction between L-serine and L-phosphoserine. Deficiency of this protein is thought to be linked to Williams syndrome.

The 3 substrates of this enzyme are O-phospho-L-serine, O-phospho-D-serine, and H₂O, whereas its 3 products are L-serine, D-serine, and phosphate.This enzyme belongs to the family of hydrolases, specifically those acting on phosphoric monoester bonds. The systematic name of this enzyme class is O-phosphoserine phosphohydrolase.