Catalyzes the conjugation of the 1'-hydroxyl group of D-myo-inositol-3-phosphate (also named L-myo-inositol-1-phosphate) with a lipid tail of cytidine diphosphate diacylglycerol (CDP-DAG), forming phosphatidylinositol phosphate (PIP) and CMP. PIP is a precursor of phosphatidylinositol (PI) which is an essential lipid for mycobacteria required for formation of their cell wall. 1D-myo-inositol 3-phosphate + a CDP-1,2-diacyl-sn-glycerol = a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-3-phosphate) + CMP + H(+) 1,2-di-(9Z-octadecenoyl)-sn-glycero-3-cytidine-5'-diphosphate + 1D-myo-inositol 3-phosphate = 1,2-di-(9Z-octadecenoyl)-sn-glycero-3-phospho-(1D-myo-inositol-3-phosphate) + CMP + H(+) Contains a di-nuclear catalytic Mg(2+) center. Phospholipid metabolism; phosphatidylinositol phosphate biosynthesis. Homodimer. M.tuberculosis PgsA1 has been identified as a promising candidate for drug development because of its vital role in growth and proliferation of the pathogen as well as the differences between eukaryotic and mycobacterial PI biosynthesis pathways. Belongs to the CDP-alcohol phosphatidyltransferase class-I family. Was orginally thought to be a phosphatidylinositol (PI) synthase.