This is the acyl carrier domain (ACP) found in fatty acid synthase subunit alpha (FAS2) EC:2.3.1.86 .The fungal type I fatty acid synthase (FAS) is a 2.6 MDa multienzyme complex, catalyzing all necessary steps for the synthesis of long acyl chains. To be catalytically competent, the FAS must be activated by a posttranslational modification of the central acyl carrier domain (ACP) by an intrinsic phosphopantetheine transferase (PPT) [1].

1: Structural basis for substrate delivery by acyl carrier protein in the yeast fatty acid synthase. Leibundgut M, Jenni S, Frick C, Ban N; Science. 2007;316:288-290. PMID:17431182

2: Inhibition of the fungal fatty acid synthase type I multienzyme complex. Johansson P, Wiltschi B, Kumari P, Kessler B, Vonrhein C, Vonck J, Oesterhelt D, Grininger M; Proc Natl Acad Sci U S A. 2008;105:12803-12808. PMID:18725634

3: Multimeric options for the auto-activation of the Saccharomyces cerevisiae FAS type I megasynthase. Johansson P, Mulinacci B, Koestler C, Vollrath R, Oesterhelt D, Grininger M; Structure. 2009;17:1063-1074. PMID:19679086