Phosphoenolpyruvate carboxylase
![Figure 1: the Phosphoenolpyruvate (PEP) carboxylase single subunit structure (generated by PyMOL).](/Images/godic/202502/02/PEP_Carboxylase_Structure5126.png")
![Figure 2: the Phosphoenolpyruvate (PEP) carboxylase enzymatic mechanism converting bicarbonate and PEP to oxaloacetate and phosphate.](/Images/godic/202502/02/PEP_Carboxylase_Mechanism5126.png")
![Figure 3: the Phosphoenolpyruvate (PEP) carboxylase regulation pathways.](/Images/godic/202502/02/PEP_Carboxylase_Regulation5127.png")
Phosphoenolpyruvate carboxylase (also known as PEP carboxylase, PEPCase, or PEPC; EC 4.1.1.31, PDB ID: 3ZGE) is an enzyme in the family of carboxy-lyases found in plants and some bacteria that catalyzes the addition of bicarbonate (HCO3) to phosphoenolpyruvate (PEP) to form the four-carbon compound oxaloacetate and inorganic phosphate: