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 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 (Probable). 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). With HSD17B4, catalyzes the hydration of trans-2-enoyl-CoA and the dehydrogenation of 3-hydroxyacyl-CoA, but with opposite chiral specificity (PubMed:15060085). 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 (PubMed:15060085). 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 Enzyme activity enhanced by acetylation. Lipid metabolism; fatty acid beta-oxidation. Monomer. Liver and kidney. Strongly expressed in the terminal segments of the proximal tubule. Lower amounts seen in the brain. Acetylated, leading to enhanced enzyme activity. Acetylation is enhanced by up to 80% after treatment either with trichostin A (TSA) or with nicotinamide (NAM) with highest increase on Lys-346. Acetylation and enzyme activity increased by about 1.5% on addition of fatty acids. The disease is caused by variants affecting the gene represented in this entry. Absent in patients suffering with peroxisomal disorders such as Zellweger syndrome, neonatal adrenoleukodystrophy and infantile Refsum disease. 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.