6 methylsalicylic acid synthase

In enzymology, a 6-methylsalicylic-acid synthase (EC 2.3.1.165) is an polyketide synthase that catalyzes the chemical reaction

acetyl-CoA + 3 malonyl-CoA + NADPH + H⁺ ⇌ 6-methylsalicylate + 4 CoA + 3 CO₂ + NADP⁺ + H₂O

The 4 substrates of this enzyme are acetyl-CoA, malonyl-CoA, NADPH, and H⁺, whereas its 5 products are 6-methylsalicylate, CoA, CO₂, NADP⁺, and H₂O.

This enzyme belongs to the family of transferases, specifically those acyltransferases transferring groups other than aminoacyl groups. The systematic name of this enzyme class is acyl-CoA:malonyl-CoA C-acyltransferase (decarboxylating, oxoacyl-reducing, thioester-hydrolysing and cyclizing). Other names in common use include MSAS, and 6-methylsalicylic acid synthase.