Bifunctional enzyme that catalyzes the fourth and fifth sequential steps of CoA biosynthetic pathway. The fourth reaction is catalyzed by the phosphopantetheine adenylyltransferase, coded by the coaD domain; the fifth reaction is catalyzed by the dephospho-CoA kinase, coded by the coaE domain. May act as a point of CoA biosynthesis regulation. (R)-4'-phosphopantetheine + ATP + H(+) = 3'-dephospho-CoA + diphosphate 3'-dephospho-CoA + ATP = ADP + CoA + H(+) Cofactor biosynthesis; coenzyme A biosynthesis; CoA from (R)-pantothenate: step 4/5. Cofactor biosynthesis; coenzyme A biosynthesis; CoA from (R)-pantothenate: step 5/5. Monomer. The protein is mainly present in the mitochondrial matrix, probably anchored to the inner mitochondrial membrane, but this protein is also present in cell lysate. The N-terminus is blocked. In the central section; belongs to the eukaryotic CoaD family.