Biosynthesis
Phosphatidylglycerol (PG) is formed via a complex sequential pathway whereby phosphatidic acid (PA) is first converted to CDP-diacylglyceride by the enzyme CDP-diacylglyceride synthase. Then a PGP synthase enzyme exchanges glycerol-3-phosphate (G3P) for cytidine monophosphase (CMP), forming the temporary intermediate phosphatidylglycerolphosphate (PGP). PG is finally synthesized when a PGP phosphatase enzyme catalyzes the immediate dephosphorylation of the PGP intermediate to form PG. In bacteria, another membrane phospholipid known as cardiolipin can be synthesized by condensing two molecules of phosphatidylglycerol; a reaction catalyzed by the enzyme cardiolipin-synthase. In eukaryotic mitochondria phosphatidylglycerol is converted to cardiolipin by reacting with a molecule of cytidine diphosphate diglyceride in a reaction catalyzed by cardiolipin synthase. ==See also==