Classification of Ser/Thr phosphatase. Ser/Thr phosphatases are classified into phosphoprotein phosphatases (PPP) and Mg2＋-dependent protein phosphatase (PPM/PP2C). The PPP family can be further divided into seven subgroups: PP1, PP2A, PP2B, PP4, PP5, PP6, and PP7. Most Ser/Thr phosphatases are in the complex with their catalytic and regulatory subunits, except for PP5, PP7, and PP2C, which are solely comprised of catalytic subunits.
