Acyl carrier protein synthase

In enzymology and molecular biology, a holo- synthase (ACPS, EC 2.7.8.7) is an enzyme that catalyzes the chemical reaction: In enzymology and molecular biology, a holo- synthase (ACPS, EC 2.7.8.7) is an enzyme that catalyzes the chemical reaction: This enzyme belongs to the family of transferases, specifically those transferring non-standard substituted phosphate groups. It is also known as 4'-phosphopantetheinyl transferase after the group it transfers. All ACPS enzymes known so far are evolutionally related to each other in a single superfamily of proteins. It transfers a 4'-phosphopantetheine (4'-PP) moiety from coenzyme A (CoA) to an invariant serine in an acyl carrier protein (ACP), a small protein responsible for acyl group activation in fatty acid biosynthesis. This post-translational modification renders holo-ACP capable of acyl group activation via thioesterification of the cysteamine thiol of 4'-PP. This superfamily consists of two subtypes: the trimeric ACPS type such as E. coli ACPS and the monomeric Sfp (PCP-synthesizing) type such as B. subtilis SFP. Structures from both families are now known. The active site accommodates a magnesium ion. The most highly conserved regions of the protein are involved in binding the magnesium ion. The systematic name of this enzyme class is CoA-:apo- 4'-pantetheinephosphotransferase. Other names in common use, disregarding the synthetase/synthase spelling difference, include acyl carrier protein holoprotein synthetase, holo-ACP synthetase, coenzyme A:fatty acid synthetase apoenzyme 4'-phosphopantetheine, acyl carrier protein synthetase (ACPS), PPTase, acyl carrier protein synthase, P-pant transferase, and CoA:apo- pantetheinephosphotransferase. As of late 2007, 8 structures have been solved for this class of enzymes, with PDB accession codes 1F7L, 1F7T, 1F80, 1FTE, 1FTF, 1FTH, 2JBZ, and 2JCA.