Involved in some intermediate steps for the synthesis of the antibiotic polyketide bacillaene which is involved in secondary metabolism. Binds 5 phosphopantetheines covalently. Antibiotic biosynthesis; bacillaene biosynthesis. The acyl carrier 2 domain binds glycine. Belongs to the ATP-dependent AMP-binding enzyme family. Was originally thought to be two separate ORFs named pksJ and pksK.