Reversibly transfers an adenylyl group from ATP to 4'-phosphopantetheine, yielding dephospho-CoA (dPCoA) and pyrophosphate. (R)-4'-phosphopantetheine + ATP + H(+) = 3'-dephospho-CoA + diphosphate Regulated by Coenzyme A (CoA) through feedback inhibition. kcat is 288.5 min(-1) for the reverse reaction, with diphosphate and 3'-dephospho-CoA as substrates, which is nearly identical to that of the forward reaction fitted to the Hill equation. The enzyme seems to utilize a nonrapid-equilibrium random bi-bi mechanism with a preferred pathway to the ternary complex. A sigmoidal response is observed when ATP was varied at different fixed concentrations of pantetheine 4'-phosphate. Also exhibits nonhyperbolic kinetics when pantetheine 4'-phosphate was varied at a fixed saturating concentration of ATP. Cofactor biosynthesis; coenzyme A biosynthesis; CoA from (R)-pantothenate: step 4/5. Homohexamer; dimer of trimers. Belongs to the bacterial CoaD family.