Non-reducing polyketide synthase; part of the gene cluster that mediates the biosynthesis of pleosporalin A, ascomycone A, as well as a third cryptic naphthoquinone derived pigment, all responsible for the coloration of conidia (PubMed:28471414, PubMed:35351612). The non-reducing polyketide synthase pgmA is responsible for the condensation of seven acetyl-CoA units to produce the cyclized heptaketide 3-acetonyl-1,6,8-trihydroxy-2-naphthaldehyde (PubMed:35351612). The pathway begins with the biosynthesis of the cyclized heptaketide 3-acetonyl-1,6,8-trihydroxy-2-naphthaldehyde by the NR-PKS pgmA. The C-6 hydroxyl group is further methylated by the O-methyltransferase pgmB to yield fusarubinaldehyde which is in turn oxidized by the cytochrome P450 monooxygenase pgmC at C-9. The C-1 hydroxyl group is then methylated spontaneously. Although pgmE, pgmD and pgmH are essential for the production of pleosporalin A, it is not the case for the 2 other final products and it remains difficult to assign a specific function to each enzyme. PgmF and pgmG seem not to be involved in pigment biosynthesis although they were regulated by the cluster-specific transcription factor pgmR (PubMed:35351612) (Probable). Pigment biosynthesis. Secondary metabolite biosynthesis. Expression is positively regulated by the pgm cluster-specific transcription factor pgmR. 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 back-bone; 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; and 2 acyl-carrier protein (ACP) that serve as the tethers of the growing and complete polyketide via their phosphopantetheinyl arm. At the C-terminus, FSR1 exhibits a reductase (R) domain instead of the canonical TE domain. In contrast to TE and TE/CLC domains, R domains show sequence similarities to the short-chain dehydrogenase/reductase (SDR) superfamily, exhibiting Rossman fold structure and nucleotide binding motifs. Abolished completely the production of the naphthoquinones derived pigments.