Description
Enoyl-CoA hydratase () (ECH) PUBMED:2806264 and 3-2trans-enoyl-CoA isomerase () (ECI) PUBMED:1958319 are two enzymes involved in fatty acid metabolism. ECH catalyzes the hydratation of 2-trans-enoyl-CoA into 3-hydroxyacyl-CoA and ECI shifts the 3- double bond of the intermediates of unsaturated fatty acid oxidation to the 2-trans position.
Most eukaryotic cells have two fatty-acid beta-oxidation systems, one located in mitochondria and the other in peroxisomes. In mitochondria, ECH and ECI are separate yet structurally related monofunctional enzymes. Peroxisomes contain a trifunctional enzyme PUBMED:2303409 consisting of an N-terminal domain that bears both ECH and ECI activity, and a C-terminal domain responsible for 3-hydroxyacyl-CoA dehydrogenase (HCDH) activity.
In Escherichia coli (gene fadB) and Pseudomonas fragi (gene faoA), ECH and ECI are also part of a multifunctional enzyme which contains both a HCDH and a 3-hydroxybutyryl-CoA epimerase domain PUBMED:2204034.
A number of other proteins have been found to be evolutionary related to the ECH/ECI enzymes or domains:
- 3-hydroxbutyryl-coa dehydratase () (crotonase), a bacterial enzyme involved in the butyrate/butanol-producing pathway.
- Naphthoate synthase () (DHNA synthetase) (gene menB) PUBMED:1629163, a bacterial enzyme involved in the biosynthesis of menaquinone (vitamin K2). DHNA synthetase converts O-succinyl-benzoyl-CoA (OSB-CoA) to 1,4-dihydroxy-2- naphthoic acid (DHNA).
- 4-chlorobenzoate dehalogenase () PUBMED:1351742, a Pseudomonas enzyme which catalyzes the conversion of 4-chlorobenzoate-CoA to 4-hydroxybenzoate-CoA.
- A Rhodobacter capsulatus protein of unknown function (ORF257) PUBMED:1743516.
- Bacillus subtilis putative polyketide biosynthesis proteins pksH and pksI.
- E. coli carnitine racemase (gene caiD) PUBMED:7815937.
- E. coli hypothetical protein ygfG.
- Yeast hypothetical protein YDR036c.
Description text from InterPro entry IPR001753
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