Involved in the biosynthesis of the antifungal antibiotic ansatrienin A (mycotrienin I) (PubMed:1597409, PubMed:8955309). Catalyzes three of the reductive steps involved in the formation of the cyclohexanecarboxylic acid (CHC) moiety of ansatrienin from shikimic acid (PubMed:8955309). Can use 3,4-dihydroxycyclohexa-1,5-diene-1-carbonyl-CoA, 5-hydroxycyclohex-1-ene-1-carbonyl-CoA and cyclohex-1-ene-1-carbonyl-CoA as substrates (PubMed:8955309, PubMed:1597409, PubMed:10973220). (4R,5R)-4,5-dihydroxycyclohex-2-ene-1-carbonyl-CoA + NADP(+) = (3R,4R)-3,4-dihydroxycyclohexa-1,5-diene-1-carbonyl-CoA + H(+) + NADPH (3S)-3-hydroxycyclohexane-1-carbonyl-CoA + NADP(+) = (5S)-5-hydroxycyclohex-1-ene-1-carbonyl-CoA + H(+) + NADPH cyclohexane-1-carbonyl-CoA + NADP(+) = cyclohex-1-ene-1-carbonyl-CoA + H(+) + NADPH Inhibited by the thiol inhibitors p-chloromercuribenzoate, N-ethylmaleimide and iodoacetamide. Also inhibited by various divalent cations. Optimum pH is 7.5. Optimum temperature is 30 degrees Celsius. Antibiotic biosynthesis. Homodimer. Deletion mutant loses the ability to synthesize either cyclohexanecarboxylic acid or ansatrienin. Belongs to the short-chain dehydrogenases/reductases (SDR) family.