a 1,2-diacyl-sn-glycero-3-phosphate + CTP + H(+) = a CDP-1,2-diacyl-sn-glycerol + diphosphate Phospholipid metabolism; CDP-diacylglycerol biosynthesis; CDP-diacylglycerol from sn-glycerol 3-phosphate: step 3/3. Belongs to the CDS family. Truncated N-terminus. Truncated N-terminus.