Highly reducing polyketide synthase (HR-PKS); part of the gene cluster that mediates the biosynthesis of cordypyrones A and B, 2 pyrones that show modest activities against pathogenic bacteria including methicillin-resistant Staphylococcus aureus (MRSA), Mycobacterium tuberculosis and Bacillus cereus (PubMed:34548637). The HR-PKS milA catalyzes the formation of cordypyrones A via condensation of one acetate with 10 malonate units (PubMed:34548637). Since milA lacks an enoyl reductase domain, the 2 beta-keto processing domains DH and KR of milA collaborate with the trans-enoyl reductase milB to catalyze the different levels of reduction (PubMed:34548637). The cytochrome P450 monooxygenase milC then hydroxylates the C-22 of cordypyrones A to yield cordypyrones B (PubMed:34548637). acetyl-CoA + 3 AH2 + 18 H(+) + 10 malonyl-CoA + 8 NADPH = 3 A + 10 CO2 + 11 CoA + cordypyrone A + 8 H2O + 8 NADP(+) Binds 1 phosphopantetheine covalently. Secondary metabolite biosynthesis. 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 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.