IUBMB Enzyme Nomenclature


Accepted name: 4-hydroxybutanoyl-CoA dehydratase

Reaction: 4-hydroxybutanoyl-CoA = (E)-but-2-enoyl-CoA + H2O

For diagram of reaction click here.

Glossary: 4-hydroxybutanoyl-CoA = 4-hydroxybutyryl-CoA
(E)-but-2-enoyl-CoA = crotonyl-CoA

Systematic name: 4-hydroxybutanoyl-CoA hydro-lyase

Comments: Contains FAD and a [4Fe-4S] iron-sulfur cluster. The enzyme has been characterized from several microorganisms, including Clostridium kluyveri, where it participates in succinate fermentation [1,2], Clostridium aminobutyricum, where it participates in 4-aminobutyrate degradation [3,4], and Metallosphaera sedula, where it participates in the 3-hydroxypropionate/4-hydroxybutyrate cycle, an autotrophic CO2 fixation pathway found in some thermoacidophilic archaea [5].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Bartsch, R.G. and Barker, H.A. A vinylacetyl isomerase from Clostridium kluyveri. Arch. Biochem. Biophys. 92 (1961) 122-132. [PMID: 13687513]

2. Scherf, U., Sohling, B., Gottschalk, G., Linder, D. and Buckel, W. Succinate-ethanol fermentation in Clostridium kluyveri: purification and characterisation of 4-hydroxybutyryl-CoA dehydratase/vinylacetyl-CoA Δ32-isomerase. Arch. Microbiol. 161 (1994) 239-245. [PMID: 8161284]

3. Scherf, U. and Buckel, W. Purification and properties of an iron-sulfur and FAD-containing 4-hydroxybutyryl-CoA dehydratase/vinylacetyl-CoA Δ32-isomerase from Clostridium aminobutyricum. Eur. J. Biochem. 215 (1993) 421-429. [PMID: 8344309]

4. Muh, U., Cinkaya, I., Albracht, S.P. and Buckel, W. 4-Hydroxybutyryl-CoA dehydratase from Clostridium aminobutyricum: characterization of FAD and iron-sulfur clusters involved in an overall non-redox reaction. Biochemistry 35 (1996) 11710-11718. [PMID: 8794752]

5. Berg, I.A., Kockelkorn, D., Buckel, W. and Fuchs, G. A 3-hydroxypropionate/4-hydroxybutyrate autotrophic carbon dioxide assimilation pathway in Archaea. Science 318 (2007) 1782-1786. [PMID: 18079405]

[EC created 2009]

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