Thioesterase that has relatively broad substrate specificity, hydrolyzing primarily medium- and long-chain acyl-CoA substrates to free fatty acids and CoA (PubMed:1645722, PubMed:24271180, PubMed:20547355). Functions in the thioesterase-dependent pathway of beta-oxidation of oleate and conjugated linoleate ((9Z,11E)-octadecadienoate or CLA), which provides all energy and carbon precursors required for the growth of E.coli. Thus, supports growth on oleate or conjugated linoleate as the sole source of carbon by hydrolyzing 3,5-tetradecadienoyl-CoA, the terminal metabolite of oleate beta-oxidation via the alternative thioesterase-dependent pathway, and 3,5-dodecadienoyl-CoA, the end product of CLA beta-oxidation, respectively (PubMed:18702504, PubMed:14707139). Seems to be involved in 3-hydroxyalkanoate production in E.coli (PubMed:20547355). a fatty acyl-CoA + H2O = a fatty acid + CoA + H(+) H2O + tetradecanoyl-CoA = CoA + H(+) + tetradecanoate (3E,5Z)-tetradecadienoyl-CoA + H2O = (3E,5Z)-tetradecadienoate + CoA + H(+) dodecanoyl-CoA + H2O = CoA + dodecanoate + H(+) (3Z,5E)-dodecadienoyl-CoA + H2O = (3Z,5E)-dodecadienoate + CoA + H(+) decanoyl-CoA + H2O = CoA + decanoate + H(+) H2O + octanoyl-CoA = CoA + H(+) + octanoate H2O + hexanoyl-CoA = CoA + H(+) + hexanoate H2O + pentanoyl-CoA = CoA + H(+) + pentanoate butanoyl-CoA + H2O = butanoate + CoA + H(+) 4-methylpentanoyl-CoA + H2O = 4-methylpentanoate + CoA + H(+) (3R)-3-hydroxypentanoyl-CoA + H2O = (3R)-3-hydroxypentanoate + CoA + H(+) (3S)-3-hydroxypentanoyl-CoA + H2O = (3S)-3-hydroxypentanoate + CoA + H(+) H2O + hexadecanoyl-CoA = CoA + H(+) + hexadecanoate H2O + octadecanoyl-CoA = CoA + H(+) + octadecanoate (9Z)-octadecenoyl-CoA + H2O = (9Z)-octadecenoate + CoA + H(+) (3R)-3-hydroxybutanoyl-CoA + H2O = (R)-3-hydroxybutanoate + CoA + H(+) (3S)-3-hydroxybutanoyl-CoA + H2O = (S)-3-hydroxybutanoate + CoA + H(+) (2E)-dodecenoyl-CoA + H2O = (2E)-dodecenoate + CoA + H(+) 3-oxododecanoyl-CoA + H2O = 3-oxododecanoate + CoA + H(+) 3-hydroxydodecanoyl-CoA + H2O = 3-hydroxydodecanoate + CoA + H(+) Inhibited by iodoacetamide and diethylpyrocarbonate in vitro, but is insensitive to iodoacetate treatment. kcat is 83 sec(-1) with decanoyl-CoA as substrate. Homotetramer. Deletion of this gene decreases the growth rate of cells on conjugated linoleate but not on palmitate (PubMed:18702504). Deletion of this gene also decreases 3-hydroxybutanoate, 3-hydroxyhexanoate, 3-hydroxyoctanoate, and hexanoate in medium after cultivation with oleate as a sole carbon source (PubMed:20547355). Has been used in the engineered enzymatic high-level production of enantiomerically pure (R)- and (S)-3-hydroxybutanoate, used as a building block for the synthesis of optically active fine chemicals, such as vitamins, antibiotics, pheromones, and flavor compounds. Chemical synthesis of chiral 3-hydroxybutanoate (3HB) is not economically feasible. Belongs to the C/M/P thioester hydrolase family.