Peroxisomal trifunctional enzyme possessing 2-enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, and delta 3, delta 2-enoyl-CoA isomerase activities. Catalyzes two of the four reactions of the long straight chain fatty acids peroxisomal beta-oxidation pathway (By similarity). Can also use branched-chain fatty acids such as 2-methyl-2E-butenoyl-CoA as a substrate, which is hydrated into (2S,3S)-3-hydroxy-2-methylbutanoyl-CoA (By similarity). Optimal isomerase for 2,5 double bonds into 3,5 form isomerization in a range of enoyl-CoA species. Also able to isomerize both 3-cis and 3-trans double bonds into the 2-trans form in a range of enoyl-CoA species (By similarity). Regulates the amount of medium-chain dicarboxylic fatty acids which are essential regulators of all fatty acid oxidation pathways (By similarity). Also involved in the degradation of long-chain dicarboxylic acids through peroxisomal beta-oxidation (By similarity). a (3S)-3-hydroxyacyl-CoA = a (2E)-enoyl-CoA + H2O a 4-saturated-(3S)-3-hydroxyacyl-CoA = a (3E)-enoyl-CoA + H2O a (3Z)-enoyl-CoA = a 4-saturated (2E)-enoyl-CoA a (3E)-enoyl-CoA = a 4-saturated (2E)-enoyl-CoA a (3S)-3-hydroxyacyl-CoA + NAD(+) = a 3-oxoacyl-CoA + H(+) + NADH (2S,3S)-3-hydroxy-2-methylbutanoyl-CoA = (2E)-2-methylbut-2-enoyl-CoA + H2O (3S)-hydroxyhexadecanoyl-CoA + NAD(+) = 3-oxohexadecanoyl-CoA + H(+) + NADH (3S)-hydroxyhexadecanoyl-CoA = (2E)-hexadecenoyl-CoA + H2O (2E)-hexadecenedioyl-CoA + H2O = (3S)-hydroxyhexadecanedioyl-CoA (3S)-hydroxyhexadecanedioyl-CoA + NAD(+) = 3-oxohexadecanedioyl-CoA + H(+) + NADH (3E,5Z)-tetradecadienoyl-CoA = (2E,5Z)-tetradecadienoyl-CoA (3E,5Z)-octadienoyl-CoA = (2E,5Z)-octadienoyl-CoA (3S)-hydroxydecanoyl-CoA + NAD(+) = 3-oxodecanoyl-CoA + H(+) + NADH (3E)-decenoyl-CoA = (2E)-decenoyl-CoA (3Z)-hexenoyl-CoA = (2E)-hexenoyl-CoA (3E)-hexenoyl-CoA = (2E)-hexenoyl-CoA (3S)-hydroxydecanoyl-CoA = (2E)-decenoyl-CoA + H2O (3S)-hydroxyhexanoyl-CoA = (2E)-hexenoyl-CoA + H2O Lipid metabolism; fatty acid beta-oxidation. Monomer. In the N-terminal section; belongs to the enoyl-CoA hydratase/isomerase family. In the C-terminal section; belongs to the 3-hydroxyacyl-CoA dehydrogenase family.