Structural highlights
Function
[HDVD_CLOAM] Catalyzes the reversible conversion of 4-hydroxybutyryl-CoA to crotonyl-CoA. The mechanism of the reaction seems to go through three steps: (1) the FAD-dependent oxidation of 4-hydroxybutyryl-CoA to 4-hydroxycrotonyl-CoA; (2) the hydroxyl group is substituted by a hydride derived from the now reduced FAD in an SN2' reaction leading to vinylacetyl-CoA; (3) isomerization to yield crotonyl-CoA.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Dehydratases catalyze the breakage of a carbon-oxygen bond leading to unsaturated products via the elimination of water. The 1.6-A resolution crystal structure of 4-hydroxybutyryl-CoA dehydratase from the gamma-aminobutyrate-fermenting Clostridium aminobutyricum represents a new class of dehydratases with an unprecedented active site architecture. A [4Fe-4S](2+) cluster, coordinated by three cysteine and one histidine residues, is located 7 A from the Re-side of a flavin adenine dinucleotide (FAD) moiety. The structure provides insight into the function of these ubiquitous prosthetic groups in the chemically nonfacile, radical-mediated dehydration of 4-hydroxybutyryl-CoA. The substrate can be bound between the [4Fe-4S](2+) cluster and the FAD with both cofactors contributing to its radical activation and catalytic conversion. Our results raise interesting questions regarding the mechanism of acyl-CoA dehydrogenases, which are involved in fatty acid oxidation, and address the divergent evolution of the ancestral common gene.
Crystal structure of 4-hydroxybutyryl-CoA dehydratase: radical catalysis involving a [4Fe-4S] cluster and flavin.,Martins BM, Dobbek H, Cinkaya I, Buckel W, Messerschmidt A Proc Natl Acad Sci U S A. 2004 Nov 2;101(44):15645-9. Epub 2004 Oct 20. PMID:15496473[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Martins BM, Dobbek H, Cinkaya I, Buckel W, Messerschmidt A. Crystal structure of 4-hydroxybutyryl-CoA dehydratase: radical catalysis involving a [4Fe-4S] cluster and flavin. Proc Natl Acad Sci U S A. 2004 Nov 2;101(44):15645-9. Epub 2004 Oct 20. PMID:15496473 doi:0403952101
