1u8v

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=SF4:IRON/SULFUR+CLUSTER'>SF4</scene></td></tr>

[[https://www.uniprot.org/uniprot/HDVD_CLOAM 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.

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== 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<ref>PMID:15496473</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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== References ==

<references/>

[[Category: Buckel, W]]

[[Category: Cinkaya, I]]

[[Category: Dobbek, H]]

[[Category: Martins, B M]]

[[Category: Messerschmidt, A]]

[[Category: Lyase]]