acetyl-CoA + 3 malonyl-CoA + NADPH + H+ = 6-methylsalicylate + 4 CoA + 3 CO2 + NADP+ + H2O
For diagram of polyketides biosynthesis, click here
MSAS; 6-methylsalicylic acid synthase
acyl-CoA:malonyl-CoA C-acyltransferase (decarboxylating, oxoacyl-reducing, thioester-hydrolysing and cyclizing)
A multienzyme complex with a 4′-phosphopantetheine prosthetic group on the acyl carrier protein. It has a similar sequence to vertebrate type I fatty acid synthase. Acetoacetyl-CoA can also act as a starter molecule.
Spencer, J.B. and Jordan, P.M. Purification and properties of 6-methylsalicylic acid synthase from Penicillium patulum. Biochem. J.288 (1992) 839–846. [PMID: 1471999]
Child, C.J., Spencer, J.B., Bhogal, P. and Shoolingin-Jordan, P.M. Structural similarities between 6-methylsalicylic acid synthase from Penicillium patulum and vertebrate type I fatty acid synthase: evidence from thiol modification studies. Biochemistry35 (1996) 12267–12274. [PMID: 8823160]
Richardson, M.T., Pohl, N.L., Kealey, J.T. and Khosla, C. Tolerance and specificity of recombinant 6-methylsalicyclic acid synthase. Metab. Eng.1 (1999) 180–187. [PMID: 10935930]