Isoepoxydon dehydrogenase patN
Aspergillus clavatus (strain ATCC 1007 / CBS 513.65 / DSM 816 / NCTC 3887 / NRRL 1)
Isoepoxydon dehydrogenase; part of the gene cluster that mediates the biosynthesis of patulin, an acetate-derived tetraketide mycotoxin produced by several fungal species that shows antimicrobial properties against several bacteria (PubMed:19383676, PubMed:24334092). The pathway begins with the synthesis of 6-methylsalicylic acid by the polyketide synthase (PKS) patK via condensation of acetate and malonate units (PubMed:19383676). PatG then catalyzes the decarboxylation of 6-methylsalicylic acid to yield m-cresol (PubMed:24334092). The cytochrome P450 monooxygenase patH then converts m-cresol to m-hydroxybenzyl alcohol, which is further converted to gentisyl alcohol by the cytochrome P450 monooxygenase patI (PubMed:19383676). The conversion of gentisyl alcohol to two-ring compound neopatulin remains a matter of speculation, but it involves at least two intermediates, isoepoxydon and phyllostin (PubMed:19383676). PatN catalyzes the transformation of isoepoxydon into phyllostin (PubMed:19383676). The last part of the biosynthetic pathway involves the conversion of neopatulin to ascladiol followed by the transformation of the latter into patulin (PubMed:19383676).
Belongs to the short-chain dehydrogenases/reductases (SDR) family.