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 is also present in cell lysate. Expressed in all tissues examined including brain, heart, skeletal muscle, colon, thymus, spleen, kidney, liver, small intestine, placenta, lung and peripheral blood leukocyte. Lowest expression in peripheral blood leukocytes and highest in kidney and liver. Isoform 2 is expressed mainly in the brain. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. In the central section; belongs to the eukaryotic CoaD family. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus.