Catalyzes the NADPH-dependent reduction of acrylyl-CoA to propanoyl-CoA. Is essential for growth with 3-hydroxypropanoate as a sole carbon source. Restores acrylate resistance when expressed in the E.coli strain K12 acuI deletion. NADP(+) + propanoyl-CoA = acryloyl-CoA + H(+) + NADPH Homodimer. Moderately induced by acrylate and dimethylsulfonioproprionate (DMSP), as well as by 3-hydroxypropanoate. Part of the acuR-acuI-dddL operon. Increased sensitivity to acrylate on plates, decreased ability to degrade acrylate (PubMed:21249136). No effect during photoheterotropic (anaerobic/light) growth on succinate, no growth on 3-hydroxypropionate under the same conditions. Loss of 3-hydroxypropanoate and acrylate-dependent oxidation of NADPH (PubMed:22056933). The zinc-binding residues of the alcohol dehydrogenase family are not conserved. Belongs to the zinc-containing alcohol dehydrogenase family. Acrylyl-CoA reductase subfamily.