CDPdiacylglycerol-Serine O-Phosphatidyltransferase: An enzyme that catalyzes the formation of phosphatidylserine and CMP from CDPdiglyceride plus serine. EC 18.104.22.168.Cytidine Diphosphate Diglycerides: The ester of diacylglycerol with the terminal phosphate of cytidine diphosphate. It serves as an intermediate in the biosynthesis of phosphatidylethanolamine and phosphatidylserine in bacteria.Phosphotransferases: A rather large group of enzymes comprising not only those transferring phosphate but also diphosphate, nucleotidyl residues, and others. These have also been subdivided according to the acceptor group. (From Enzyme Nomenclature, 1992) EC 2.7.