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	PROSITE documentation PDOC00150 [for PROSITE entry PS00166]

Enoyl-CoA hydratase/isomerase signature

Enoyl-CoA hydratase (EC 4.2.1.17) (ECH) [1] and D3,D2-enoyl-CoA isomerase (EC 5.3.3.8) (ECI) [2] 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 β-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 [3] 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 [4].

A number of other proteins have been found to be evolutionary related to the ECH/ECI enzymes or domains:

• 3-hydroxbutyryl-coa dehydratase (EC 4.2.1.55) (crotonase), a bacterial enzyme involved in the butyrate/butanol-producing pathway.
• Naphthoate synthase (EC 4.1.3.36) (DHNA synthase) (gene menB) [5], a bacterial enzyme involved in the biosynthesis of menaquinone (vitamin K2). DHNA synthase converts O-succinyl-benzoyl-CoA (OSB-CoA) to 1,4-dihydroxy-2- naphthoic acid (DHNA).
• 4-chlorobenzoate dehalogenase (EC 3.8.1.6) [6], a Pseudomonas enzyme which catalyzes the conversion of 4-chlorobenzoate-CoA to 4-hydroxybenzoate-CoA.
• A Rhodobacter capsulatus protein of unknown function (ORF257) [7].
• Bacillus subtilis putative polyketide biosynthesis proteins pksH and pksI.
• Escherichia coli carnitine racemase (gene caiD) [8].
• Escherichia coli hypothetical protein ygfG.
• Yeast hypothetical protein YDR036c.

As a signature pattern for these enzymes, we selected a conserved region rich in glycine and hydrophobic residues.

Expert(s) to contact by email:

Hofmann K.

Last update:

December 2004 / Pattern and text revised.

PROSITE method (with tools and information) covered by this documentation:

ENOYL_COA_HYDRATASE, PS00166; Enoyl-CoA hydratase/isomerase signature  (PATTERN)

• Consensus pattern:
  [LIVM]-[STAG]-x-[LIVM]-[DENQRHSTA]-G-x(3)-[AG](3)-x(4)-[LIVMST]-x-[CSTA]-[DQHP]-[LIVMFYA]
• Sequences in UniProtKB/Swiss-Prot known to belong to this class: 375
  • detected by PS00166: 218 (true positives)
  • undetected by PS00166: 157 (155 false negatives and 2 'partials')
• Other sequence(s) in UniProtKB/Swiss-Prot detected by PS00166:
  21 false positives.
• Retrieve an alignment of UniProtKB/Swiss-Prot true positive hits:
  Clustal format, color, condensed view  /  Clustal format, color  /  Clustal format, plain text  /  Fasta format
• Retrieve the sequence logo from the alignment
• Taxonomic distribution of all UniProtKB (Swiss-Prot + TrEMBL) entries matching PS00166
• Retrieve a list of all UniProtKB (Swiss-Prot + TrEMBL) entries matching PS00166
• Scan UniProtKB (Swiss-Prot and/or TrEMBL) entries against PS00166
• View ligand binding statistics of PS00166
• Matching PDB structures: 1DCI 1DUB 1EF8 1EF9 ... [ALL]

1	Authors	Minami-Ishii N., Taketani S., Osumi T., Hashimoto T.
	Source	Eur. J. Biochem. 185:73-78(1989).

2	Authors	Mueller-Newen G., Stoffel W.
	Source	Biol. Chem. Hoppe-Seyler 372:613-624(1991).

3	Authors	Palosaari P.M., Hiltunen J.K.
	Title	Peroxisomal bifunctional protein from rat liver is a trifunctional enzyme possessing 2-enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, and delta 3, delta 2-enoyl-CoA isomerase activities.
	Source	J. Biol. Chem. 265:2446-2449(1990).
	PubMed ID	2303409

4	Authors	Nakahigashi K., Inokuchi H.
	Title	Nucleotide sequence of the fadA and fadB genes from Escherichia coli.
	Source	Nucleic Acids Res. 18:4937-4937(1990).
	PubMed ID	2204034

5	Authors	Driscoll J.R., Taber H.W.
	Title	Sequence organization and regulation of the Bacillus subtilis menBE operon.
	Source	J. Bacteriol. 174:5063-5071(1992).
	PubMed ID	1629163

6	Authors	Babbitt P.C., Kenyon G.L., Martin B.M., Charest H., Slyvestre M., Scholten J.D., Chang K.-H., Liang P.-H., Dunaway-Mariano D.
	Title	Ancestry of the 4-chlorobenzoate dehalogenase: analysis of amino acid sequence identities among families of acyl:adenyl ligases, enoyl-CoA hydratases/isomerases, and acyl-CoA thioesterases.
	Source	Biochemistry 31:5594-5604(1992).
	PubMed ID	1351742

7	Authors	Beckman D.L., Kranz R.G.
	Title	A bacterial homolog to the mitochondrial enoyl-CoA hydratase.
	Source	Gene 107:171-172(1991).
	PubMed ID	1743516

8	Authors	Eichler K., Bourgis F., Buchet A., Kleber H.-P., Mandrand-Berthelot M.-A.
	Title	Molecular characterization of the cai operon necessary for carnitine metabolism in Escherichia coli.
	Source	Mol. Microbiol. 13:775-786(1994).
	PubMed ID	7815937

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