EC Number   |
Reaction |
Reference |
|---|
    4.2.1.120 | 4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O |
- |
- |
| 4.2.1.120 | 4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O |
cleavage is achieved by a FAD-dependent oxidation of 4-hydroxybutanoyl-CoA to 4-hydroxycrotonyl-CoA. In a second step, the hydroxyl group is substituted by a hydride derived from the now reduced FAD in an SN2' reaction leading to vinylacetyl-CoA. Isomerization yields crotonyl-CoA |
2966 |
| 4.2.1.120 | 4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O |
mechanism includes a direct dehydration of of 4-hydroxybutanoyl-CoA to vinylacetyl-CoA |
698004 |
| 4.2.1.120 | 4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O |
mechanism involves transient one-electron oxidation of the substrate to activate the beta-C-H-bond. the 4Fe-4S-center could serve a structural role and/or as Lewis acid facilitating the leaving of the hydroxyl group |
696186 |
| 4.2.1.120 | 4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O |
substrate-induced radical formation in 4-hydroxybutyryl-CoA dehydratase from Clostridium aminobutyricum. The conversion of 4-hydroxybutyryl-CoA to crotonyl-CoA involves the abstraction of the 2Re and 3Si protons. The FAD semiquinone rather than the FAD quinone oxidizes the enolate (or, in the reverse direction, the dienolate) to the enoxy radical (dienoxy radical). The FADH- anion formed, in combination with the T190/E257 dyad, probably acts as a more efficient base to remove the 3Si proton. Reaction mechanism with amino acids proposed to be involved, overview. The release of H2O from Fe1 of the [4Fe-4S]2+ cluster can be facilitated by reduction to [4Fe-4S]+ |
746825 |
| 4.2.1.120 | 4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O |
the pro-(S) hydrogen atom is stereospecifically abstracted from C-3 of 4-hydroxybutanoyl-CoA, and this atom is not returned to C-4 |
697290 |
