Skip to main content
. Author manuscript; available in PMC: 2014 Mar 13.
Published in final edited form as: J Am Chem Soc. 2013 Mar 4;135(10):3752–3755. doi: 10.1021/ja311579s

Figure 3.

Figure 3

Refactoring A-74528 biosynthesis in S. coelicolor CH999. A) Strains harboring the minimal PKS enzymes (CH999/pBOOST*/pJF77) produced tri- and tetraketide shunt products. Upon the addition of the initiation module and first ring cyclase enzymes (CH999/pBOOST*/pJF76), the dodecaketides TW95a and TW95b are observed. In this case the initiation module appears to have failed to provide the appropriate hexadienyl starting unit to this major polyketide product. B) Proper function of the initiation module along with addition of the oxygenase SanJ (CH999/pBOOST*/pJF111) afforded a strain capable of producing A-74528. As in previous work, 15 the origins of the hexadienyl starting unit remain unclear but are shown as acetyl-CoA and malonyl-CoA here for simplicity. C) LC-MS/MS confirmed the identity of A-74528 produced by CH999/pBOOST*/pJF111 (top panel) through comparison to an authentic standard (bottom panel). The diamond represents the A-74528 parent ion.