Phosphopantetheine-binding <p> Phosphopantetheine (or pantetheine 4' phosphate) is the prosthetic group of acyl carrier proteins (ACP) in some multienzyme complexes where it serves as a 'swinging arm' for the attachment of activated fatty acid and amino-acid groups [<cite idref="PUB00002372"/>].</p> <p> The amino-terminal region of the ACP proteins is well defined and consists of alpha four helices arranged in a right-handedbundle held together by interhelical hydrophobic interactions. The Asp-Ser-Leu (DSL)motif is conserved in all of the ACP sequences, and the 4'-PP prosthetic group is covalently linkedvia a phosphodiester bond to the serine residue. The DSL sequence is present at the amino terminus of helix II, a domain of the protein referred to as the recognition helix and which is responsible for theinteraction of ACPs with the enzymes of type II fatty acid synthesis [<cite idref="PUB00007945"/>].</p>