Involved in the biosynthesis of the siderophore enterobactin (enterochelin), which is a macrocyclic trimeric lactone of N-(2,3-dihydroxybenzoyl)-serine. The serine trilactone serves as a scaffolding for the three catechol functionalities that provide hexadentate coordination for the tightly ligated iron(2+) atoms. Plays an essential role in the assembly of the enterobactin by catalyzing the transfer of the 4'-phosphopantetheine (Ppant) moiety from coenzyme A to the apo-domains of both EntB (ArCP domain) and EntF (PCP domain) to yield their holo-forms which make them competent for the activation of 2,3-dihydroxybenzoate (DHB) and L-serine, respectively. apo-[aryl-carrier protein] + CoA = adenosine 3',5'-bisphosphate + H(+) + holo-[aryl-carrier protein] apo-[peptidyl-carrier protein] + CoA = adenosine 3',5'-bisphosphate + H(+) + holo-[peptidyl-carrier protein] Siderophore biosynthesis; enterobactin biosynthesis. EntB, EntD, EntE, and EntF form a multienzyme complex called enterobactin synthase. Belongs to the P-Pant transferase superfamily. EntD family. Extended N-terminus. Extended N-terminus. Extended N-terminus.