2-oxoglutarate-dependent dioxygenase; part of the gene cluster that mediates the biosynthesis of fumigermin that inhibits germination of spores of the inducing S.rapamycinicus, and thus helps the fungus to defend resources in the shared habitat against a bacterial competitor (PubMed:32083553). The partially reducing polyketide synthase fngA alone is sufficient for the production of fumigermin (PubMed:32083553). FgnA catalyzes the condensation of 3 malonyl-CoA units to an acetyl-CoA starter, and 3 methylations to yield fumigermin (PubMed:32083553). It is remarkable that the five cluster genes including fgnA are conserved in distantly related fungi, supporting the assumption of a fumigermin cluster; it is thus possible that originally all five genes were functional, but that the genes encoding tailoring enzymes became inactive from mutations, similar to the case of the fgnA gene in strains A1163 and Af293 (Probable). Binds 1 Fe(2+) ion per subunit. Expression is up-regulated during co-cultivation of A.fumigatus with Streptomyces rapamycinicus that triggersthe production of the polyketide fumigermin during the bacterial-fungal interaction. Belongs to the iron/ascorbate-dependent oxidoreductase family.