IUBMB Enzyme Nomenclature

EC 4.2.1.59

Accepted name: 3-hydroxyacyl-[acyl-carrier-protein] dehydratase

Reaction: a (3R)-3-hydroxyacyl-[acyl-carrier protein] = a trans-2-enoyl-[acyl-carrier protein] + H2O

Other name(s): fabZ (gene name); fabA (gene name); D-3-hydroxyoctanoyl-[acyl carrier protein] dehydratase; D-3-hydroxyoctanoyl-acyl carrier protein dehydratase; β-hydroxyoctanoyl-acyl carrier protein dehydrase; β-hydroxyoctanoyl thioester dehydratase; β-hydroxyoctanoyl-ACP-dehydrase; (3R)-3-hydroxyoctanoyl-[acyl-carrier-protein] hydro-lyase; (3R)-3-hydroxyoctanoyl-[acyl-carrier-protein] hydro-lyase (oct-2-enoyl-[acyl-carrier protein]-forming); 3-hydroxyoctanoyl-[acyl-carrier-protein] dehydratase

Systematic name: (3R)-3-hydroxyoctanoyl-[acyl-carrier protein] hydro-lyase (oct-2-enoyl-[acyl-carrier protein]-forming)

Comments: This enzyme is responsible for the dehydration step of the dissociated (type II) fatty-acid biosynthesis system that occurs in plants and bacteria. The enzyme uses fatty acyl thioesters of ACP in vivo. Different forms of the enzyme may have preferences for substrates with different chain length. For example, the activity of FabZ, the ubiquitous enzyme in bacteria, decreases with increasing chain length. Gram-negative bacteria that produce unsaturated fatty acids, such as Escherichia coli, have another form (FabA) that prefers intermediate chain length, and also catalyses EC 5.3.3.14, trans-2-decenoyl-[acyl-carrier protein] isomerase. Despite the differences both forms can catalyse all steps leading to the synthesis of palmitate (C16:0). FabZ, but not FabA, can also accept unsaturated substrates [4].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9030-85-7

References:

1. Mizugaki, M., Swindell, A.C. and Wkil, S.J. Intermediate- and long-chain β-hydroxyacyl-ACP dehydrases from E. coli fatty acid synthetase. Biochem. Biophys. Res. Commun. 33 (1968) 520-527. [PMID: 4881058]

2. Sharma, A., Henderson, B.S., Schwab, J.M. and Smith, J.L. Crystallization and preliminary X-ray analysis of β-hydroxydecanoyl thiol ester dehydrase from Escherichia coli. J. Biol. Chem. 265 (1990) 5110-5112. [PMID: 2180957]

3. Mohan, S., Kelly, T.M., Eveland, S.S., Raetz, C.R. and Anderson, M.S. An Escherichia coli gene (FabZ) encoding (3R)-hydroxymyristoyl acyl carrier protein dehydrase. Relation to fabA and suppression of mutations in lipid A biosynthesis. J. Biol. Chem. 269 (1994) 32896-32903. [PMID: 7806516]

4. Heath, R.J. and Rock, C.O. Roles of the FabA and FabZ β-hydroxyacyl-acyl carrier protein dehydratases in Escherichia coli fatty acid biosynthesis. J. Biol. Chem. 271 (1996) 27795-27801. [PMID: 8910376]

[EC 4.2.1.59 created 1972, modified 2012]


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