In enzymology, a phosphatidylcholine synthase (EC 2.7.8.24) is an enzyme that catalyzes the chemical reaction

CDP-diacylglycerol + choline CMP + phosphatidylcholine

Thus, the two substrates of this enzyme are CDP-diacylglycerol and choline, whereas its two products are CMP and phosphatidylcholine.

This enzyme belongs to the family of transferases, specifically those transferring non-standard substituted phosphate groups. The systematic name of this enzyme class is CDP-diacylglycerol:choline O-phosphatidyltransferase. This enzyme is also called CDP-diglyceride-choline O-phosphatidyltransferase. This enzyme participates in glycerophospholipid metabolism.

• de Rudder KE, Sohlenkamp C, Geiger O (1999). "Plant-exuded choline is used for rhizobial membrane lipid biosynthesis by phosphatidylcholine synthase". J. Biol. Chem. 274 (28): 20011–6. doi:10.1074/jbc.274.28.20011. PMID 10391951.
• Sohlenkamp C, de Rudder KE, Rohrs V, Lopez-Lara IM, Geiger O (2000). "Cloning and characterization of the gene for phosphatidylcholine synthase". J. Biol. Chem. 275 (25): 18919–25. doi:10.1074/jbc.M000844200. PMID 10858449.