Dehydrogenase; part of the gene cluster that mediates the biosynthesis of enfumafungin, a glycosylated fernene-type triterpenoid with potent antifungal activity, mediated by its interaction with beta-1,3-glucan synthase and the fungal cell wall (PubMed:30051576). The pathway begins with the terpene cyclase-glycosyl transferase fusion protein that most likely uses 2,3-oxidosqualene as substrate and catalyzes glycosylation immediately after cyclization (Probable). The fernene glycoside then could be processed by the desaturase efuI which catalyzes isomerization of a double bond established by efuA to form the core structure (Probable). The latter would then undergo a series of hydroxylations in unknown order at C-2, C-19, C-23 and C-25, which would be catalyzed by two of the three cytochrome P450 monooxygenases efuB, efuG or efuH (Probable). The hydroxy-group at C-25 becomes oxidized by the dehydrogenase efuE to enable a spontaneous, non-enzymatic hemiacetal formation with C-23 (Probable). After hydroxylation at C-2, acetylation by the acetyltransferase efuC takes place (Probable). The final steps in enfumafungin biosynthesis require expansion of the 5-membered ring by lactonization via a Baeyer-Villiger reaction mediated by one of the BGC's cytochrome P450 monooxygenases (efuB, efuG or efuH) followed by ring cleavage (Probable). This type of reaction would establish a double bond between C-20 and C-21 which could be reduced by the reductase efuL to form the final product (Probable). Secondary metabolite biosynthesis; terpenoid biosynthesis. Belongs to the D-isomer specific 2-hydroxyacid dehydrogenase family.