Involved in the final reduction of the elongation cycle of fatty acid synthesis (FAS II). Catalyzes the NADH-dependent reduction of the carbon-carbon double bond in the enoyl moiety that is covalently linked to an acyl carrier protein (ACP). It is also able to reduce trans-2-dodecenoyl-CoA (DD-CoA). a 2,3-saturated acyl-[ACP] + NAD(+) = a (2E)-enoyl-[ACP] + H(+) + NADH a 2,3-saturated acyl-CoA + NAD(+) = a (2E)-enoyl-CoA + H(+) + NADH Inhibited by triclosan. kcat is 1728 min(-1) for reductase activity with DD-CoA as substrate (without His tag). kcat is 1242 min(-1) for reductase activity with DD-CoA as substrate (with His tag). Optimum pH is 7.9. Lipid metabolism; fatty acid biosynthesis. Monomer. Belongs to the TER reductase family.