Streptomyces coelicolor phosphopantetheinyl transferase: a promiscuous activator of polyketide and fatty acid synthase acyl carrier proteins

Streptomyces coelicolor is host to a number of biosynthetic proteins requiring post-translational modification by the addition of phosphopantetheine groups. The S. coelicolor genome, was probed, in silico, with the sequence of Escherichia coli holo-Acyl Carrier Protein Synthase (ACPS). A single open reading frame (ORF) strongly matching the E. coli ACPS was discovered. The putative S. coelicolor ACPS ORF was cloned and expressed and the resulting protein purified and characterised. S. coelicolor ACPS appears to be extremely promiscuous in its substrate specificity, accepting varied acyl CoA substrates and protein substrates from Type I and Type II fatty acid synthases (FAS) as well as from Type I and Type II polyketide synthase (PKS) biosynthetic protein complexes. This phosphopantetheinyl transferase thus has high potential for the synthesis of diverse holo- and acylated acyl carrier proteins.