Non-reducing polyketide synthase; part of the gene cluster that mediates the biosynthesis of nigerpyrone and its derivatives carbonarone A and pestalamide A (PubMed:30384904). The biosynthesis pathway begins with the polyketide assembly by epaA to form phenylacetyl triketide precursor from successive condensation of two malonyl-CoA, presumably with one phenylacetyl-CoA starter unit produced by the phenylacetyl-CoA ligase epaB (PubMed:30384904). For the nigerpyrone biosynthesis, the reactive polyketide chain is released as an aldehyde through the R-domain. A nonenzymatic cyclization and dehydration may create nigerpyrone (PubMed:30384904). For the biosynthesis of carbonarone A and pestalamide A, an extra methyl group is added through the C-methyltransferase domain. Several further steps involving the dehydrogenase orf1, the cytochrome P450 monooxygenase orf2 and the FAD-dependent monooxygenase orf3 are required to form a carbonarone A precursor which is converted to carbonarone A via cyclization (PubMed:30384904). The O-acetyltransferase epaC could catalyze the transfer of 2-methylsuccinyl-CoA, a common intermediate in the ethylmalonyl-CoA pathway, to generate the final product pestalamide A (Probable). Binds 1 phosphopantetheine covalently. Secondary metabolite biosynthesis. Multidomain protein; including a starter unit:ACP transacylase (SAT) that selects the starter unit, 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 product template (PT) domain that controls the immediate cyclization regioselectivity of the reactive polyketide backbone, an acyl-carrier protein (ACP) that serves as the tether of the growing and completed polyketide via its phosphopantetheinyl arm, a methyltransferase domain and a reductive NADPH-binding domain that is required for NADPH-dependent product release. Abolishes the production of nigerpyrone, carbonarone A and pestalamide A.