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- *******************************************
- * Enoyl-CoA hydratase/isomerase signature *
- *******************************************
-
- Enoyl-CoA hydratase (EC 4.2.1.17) (ECH) [1] and 3-2trans-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 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 [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:
-
- - Naphthoate synthase (EC 4.1.3.36) (DHNA synthetase) (gene menB) [5], 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 (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].
- - Escherichia coli hypothetical protein yaaL.
- - A hypothetical yeast protein encoded in the 5'region of gene KRS1.
-
- As a signature pattern for these enzymes, we selected a conserved region rich
- in glycine and hydrophobic residues.
-
- -Consensus pattern: [LIVM]-[STA]-x-[LIVM]-[DNQSTA]-G-x(3)-[AG](3)-x(4)-[LIVM]-
- x-[CSTA]-[DHP]-[LIVMFY]
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: Pasteurella haemolytica leukotoxin.
-
- -Expert(s) to contact by email: Hofmann K.O.
- khofmann@isrec-sun1.unil.ch
-
- -Last update: June 1994 / Text revised.
-
- [ 1] Minami-Ishii N., Taketani S., Osumi T., Hashimoto T.
- Eur. J. Biochem. 185:73-78(1989).
- [ 2] Mueller-Newen G., Stoffel W.
- Biol. Chem. Hoppe-Seyler 372:613-624(1991).
- [ 3] Palosaari P.M., Hiltunen J.K.
- J. Biol. Chem. 265:2446-2449(1990).
- [ 4] Nakahigashi K., Inokuchi H.
- Nucleic Acids Res. 18:4937-4937(1990).
- [ 5] Driscoll J.R., Taber H.W.
- J. Bacteriol. 174:5063-5071(1992).
- [ 6] Babbitt P.C., Kenyon G.L., Matin B.M., Charest H., Sylvestre M.,
- Scholten J.D., Chang K.-H., Liang P.-H., Dunaway-Mariano D.
- Biochemistry 31:5594-5604(1992).
- [ 7] Beckman D.L., Kranz R.G.
- Gene 107:171-172(1991).
-