Protein Domain : 3-hydroxyacyl-CoA dehydrogenase, conserved site IPR006180

Type	Conserved_site
Description	3-hydroxyacyl-CoA dehydrogenase ( ) (HCDH) [ ] is an enzyme involved in fatty acid metabolism, it catalyzes the reduction of 3-hydroxyacyl-CoA to 3-oxoacyl-CoA. Most eukaryotic cells have 2 fatty-acid beta-oxidation systems, one located in mitochondria and the other in peroxisomes. In peroxisomes 3-hydroxyacyl-CoA dehydrogenase forms, with enoyl-CoA hydratase (ECH) and 3,2-trans-enoyl-CoA isomerase (ECI) a multifunctional enzyme where the N-terminal domain bears the hydratase/isomerase activities and the C-terminal domain the dehydrogenase activity. There are two mitochondrial enzymes: one which is monofunctional and the other which is, like its peroxisomal counterpart, multifunctional.In Escherichia coli (gene fadB) and Pseudomonas fragi (gene faoA) HCDH is part of a multifunctional enzyme which also contains an ECH/ECI domain as well as a 3-hydroxybutyryl-CoA epimerase domain [ ].The other proteins structurally related to HCDH are:Bacterial 3-hydroxybutyryl-CoA dehydrogenase ( ) which reduces 3-hydroxybutanoyl-CoA to acetoacetyl-CoA [ ].Eye lens protein lambda-crystallin [ ], which is specific to lagomorphes (such as rabbit).There are two major region of similarities in the sequences of proteins of the HCDH family, the first one located in the N-terminal, corresponds to the NAD-binding site, the second one is located in the centre of the sequence.
Short Name	3-OHacyl-CoA_DH_CS