Involved in cholesterol degradation. Catalyzes the dehydrogenation of 5OH-HIP-CoA to 5OH-HIPE-CoA. 3-[(3aS,4S,5R,7aS)-5-hydroxy-7a-methyl-1-oxo-octahydro-1H-inden-4-yl]propanoyl-CoA + A = (2E)-3-[(3aS,4S,5R,7aS)-5-hydroxy-7a-methyl-1-oxo-octahydro-1H-inden-4-yl]prop-2-enoyl-CoA + AH2 Binds 2 FAD per heterotetramer. Steroid metabolism; cholesterol degradation. Heterotetramer composed of 2 IpdE1 subunits and 2 IpdE2 subunits. Deletion mutant grows normally on glycerol but shows impaired growth on cholesterol. It accumulates 5OH-HIP in the culture supernatant. Belongs to the acyl-CoA dehydrogenase family.