A heat-stable factor, required for de novo synthesis of fatty acids in the erythromycin-producing organism Streptomyces erythraeus, has been purified to homogeneity and identified as an acyl carrier protein (ACP). We conclude that, contrary to previous belief, fatty acid synthase in S. erythraeus more closely resembles the dissociable complex of E. coli than the tightly associated, multifunctional enzyme complex found in the related actinomycete Mycobacterium smegmatis.
