Catalyzes the formation of CDP-diacylglycerol (CDP-DAG) from phosphatidic acid (PA) in the mitochondrial inner membrane. Required for the biosynthesis of the dimeric phospholipid cardiolipin, which stabilizes supercomplexes of the mitochondrial respiratory chain in the mitochondrial inner membrane. a 1,2-diacyl-sn-glycero-3-phosphate + CTP + H(+) = a CDP-1,2-diacyl-sn-glycerol + diphosphate Magnesium. Also active with cobalt or copper. Optimum pH is 7-9. Phospholipid metabolism; CDP-diacylglycerol biosynthesis; CDP-diacylglycerol from sn-glycerol 3-phosphate: step 3/3. Deficient in cardiolipin. Blocked in the import of presequence-containing proteins as well as of non-cleavable carrier proteins into mitochondria. Present with 195 molecules/cell in log phase SD medium. Belongs to the TAM41 family. Was initially identified as protein involved in the translocation of transit peptide-containing proteins across the mitochondrial inner membrane by its role in maintaining the integrity and stability of the inner membrane translocase TIM23 complex (PubMed:16943180, PubMed:16790493). It has later been shown that this phenotype can be attributed to the pleiotropic effects of mitochondria lacking cardiolipin (PubMed:19114592).