In enzymology, an alanylphosphatidylglycerol synthase is an enzyme that catalyzes the chemical reaction L-alanyl-tRNA + phosphatidylglycerol ⇌ {\displaystyle \rightleftharpoons } tRNA + 3-O-L-alanyl-1-O-phosphatidylglycerolThus, the two substrates of this enzyme are L-alanyl-tRNA and phosphatidylglycerol, whereas its two products are tRNA and 3-O-L-alanyl-1-O-phosphatidylglycerol. Wikipedia