InterPro domain: IPR009075

Acyl-CoA dehydrogenases ( 1.3.99.3 ) are a family of flavoproteins that catalyse the alpha,beta-dehydrogenation of acyl-CoA thioesters to the corresponding trans 2,3-enoyl CoA-products with the concomitant reduction of enzyme-bound FAD. Different family members share a high sequence identity, catalytic mechanisms, and structural properties, but differ in the position of their catalytic bases and in their substrate binding specificity. Butyryl-CoA dehydrogenase [ 1 ] prefers short chain substrates, medium chain- and long-chain acyl-CoA dehydrogenases prefer medium and long chain substrates, respectively, and Isovaleryl-CoA dehydrogenase [ 2 ] prefers branched-chain substrates.

The monomeric enzyme is folded into three domains of approximately equal size, where the N-terminal domain is all-alpha, the middle domain is an open [ 3 , 4 ] barrel, and the C-terminal domain is a four-helical bundle. This entry represents the C-terminal domain found in medium chain acyl-CoA dehydrogenases, as well as in the related peroxisomal acyl-CoA oxidase-II enzymes, where this domain occurs as a tandem duplication. Acyl-CoA oxidase (ACO; 1.3.3.6 ) catalyzes the first and rate-determining step of the peroxisomal beta-oxidation of fatty acids [ 5 ].

1. Crystal structure of rat short chain acyl-CoA dehydrogenase complexed with acetoacetyl-CoA: comparison with other acyl-CoA dehydrogenases. J. Biol. Chem. 277, 12200-7
2. Structure of human isovaleryl-CoA dehydrogenase at 2.6 A resolution: structural basis for substrate specificity,. Biochemistry 36, 8455-64
3. Acyl-CoA dehydrogenases. A mechanistic overview. Eur. J. Biochem. 271, 494-508
4. Acyl-CoA dehydrogenases and acyl-CoA oxidases. Structural basis for mechanistic similarities and differences. Eur. J. Biochem. 271, 483-93
5. Three-dimensional structure of the flavoenzyme acyl-CoA oxidase-II from rat liver, the peroxisomal counterpart of mitochondrial acyl-CoA dehydrogenase. J. Biochem. 131, 365-74