Highly reducing polyketide synthase; part of the gene cluster that mediates the biosynthesis of phomenoic acid, a long chain aliphatic carboxylic acid that does not appear to be essential for pathogenicity but may play a role in allowing to outcompete other fungi in the environmental niche via its antifungal properties (PubMed:23396262). The polyketide synthase produces the long methylated aliphatic carboxylic acid chain of phomenoic acid (Probable). The cluster-specific cytochrome P450 monooxygenase may then hydroxylate the methyl group of carbon 31 (Probable). The putative dehydrogenase YogA, which has no obvious role in phomenoic acid biosynthesis, may further modify phomenoic acid to produce a compound not identified yet (Probable). Secondary metabolite biosynthesis. Expression is positively regulated by the phomenoic acid biosynthesis cluster-specific transcription regulator C6TF. Multidomain protein; including a ketosynthase (KS) that catalyzes repeated decarboxylative condensation to elongate the polyketide backbone; a malonyl-CoA:ACP transacylase (MAT) that selects and transfers the extender unit malonyl-CoA; a dehydratase (DH) domain that reduces hydroxyl groups to enoyl groups; a methyltransferase (CMeT) domain responsible for the incorporation of methyl groups; an enoylreductase (ER) domain that reduces enoyl groups to alkyl group; a ketoreductase (KR) domain that catalyzes beta-ketoreduction steps; and an acyl-carrier protein (ACP) that serves as the tether of the growing and completed polyketide via its phosphopantetheinyl arm. Abolishes the production of phomenoic acid.