|Superclasses:||Reactions Classified By Conversion Type → Simple Reactions → Chemical Reactions → Protein-Modification Reactions|
|Reactions Classified By Substrate → Macromolecule Reactions → Protein-Reactions → Protein-Modification Reactions|
Enzymes and Genes:
|Escherichia coli K-12 substr. MG1655 :||β-hydroxyacyl-ACP dehydratase/isomerase
3-hydroxy-acyl-[acyl-carrier-protein] dehydratase : fabZ
|Homo sapiens :||fatty acid synthase
|Mycobacterium tuberculosis H37Rv :||fatty acid synthase
|Saccharomyces cerevisiae :||fatty acid synthase, β subunit
|Spinacia oleracea :||3-hydroxyacyl-[acp] dehydrase
Supersedes EC numbers: 184.108.40.206, 220.127.116.11, 18.104.22.168
Note that this reaction equation differs from the official Enzyme Commission reaction equation for this EC number, which can be found here .
The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.
Mass balance status: Balanced.
Enzyme Commission Primary Name for 22.214.171.124: fatty-acid synthase
Enzyme Commission Synonyms for 126.96.36.199: FASN (gene name)
Enzyme Commission Primary Name for 188.8.131.52: fatty-acyl-CoA synthase
Enzyme Commission Synonyms for 184.108.40.206: yeast fatty acid synthase, FAS1 (gene name), FAS2 (gene name)
Enzyme Commission Primary Name for 220.127.116.11: 3-hydroxyacyl-[acyl-carrier-protein] dehydratase
Enzyme Commission Synonyms for 18.104.22.168: 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
Standard Gibbs Free Energy (ΔrG'° in kcal/mol): 22.705242 [Latendresse13]
The enzyme is specific for 3-hydroxyacyl-[acyl-carrier protein] derivatives (C12 to C16), and has the highest activity on the C16 derivative.
Enzyme Commission Summary for 22.214.171.124:
The animal enzyme is a multi-functional protein catalysing the reactions of EC 126.96.36.199, [acyl-carrier-protein] S-acetyltransferase, EC 188.8.131.52, [acyl-carrier-protein] S-malonyltransferase, EC 184.108.40.206, β-ketoacyl-[acyl-carrier-protein] synthase I, EC 220.127.116.11, 3-oxoacyl-[acyl-carrier-protein] reductase, EC 18.104.22.168, 3-hydroxyacyl-[acyl-carrier-protein] dehydratase, EC 22.214.171.124, enoyl-[acyl-carrier-protein] reductase (NADPH, Re-specific) and EC 126.96.36.199, oleoyl-[acyl-carrier-protein] hydrolase. cf. EC 188.8.131.52, fatty-acyl-CoA synthase.
Enzyme Commission Summary for 184.108.40.206:
The enzyme from yeasts (Ascomycota and Basidiomycota) is a multi-functional protein complex composed of two subunits. One subunit catalyses the reactions EC 220.127.116.11, 3-oxoacyl-[acyl-carrier-protein] reductase and EC 18.104.22.168, β-ketoacyl-[acyl-carrier-protein] synthase I, while the other subunit catalyses the reactions of EC 22.214.171.124, [acyl-carrier-protein] S-acetyltransferase, EC 126.96.36.199, [acyl-carrier-protein] S-malonyltransferase, EC 188.8.131.52, 3-hydroxyacyl-[acyl-carrier-protein] dehydratase, EC 184.108.40.206, enoyl-[acyl-carrier-protein] reductase (NADPH, Si-specific) and EC 220.127.116.119, (R)-3-hydroxyacid-ester dehydrogenase. The enzyme differs from the animal enzyme (EC 18.104.22.168) in that the enoyl reductase domain requires FMN as a cofactor, and the ultimate product is an acyl-CoA (usually palmitoyl-CoA) instead of a free fatty acid.
Enzyme Commission Summary for 22.214.171.124:
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 126.96.36.199, 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 [Heath96].
Instance reaction of [a (3R)-3-hydroxyacyl-[acyl-carrier protein] → a trans-2-enoyl-[acyl-carrier protein] + H2O] (188.8.131.52/184.108.40.206/220.127.116.11):
i1: a (3R)-3-hydroxypalmitoyl-[acp] → a trans hexadecenoyl-[acp] + H2O (18.104.22.168/22.214.171.124/126.96.36.199)
Unification Links: KEGG:R04462
Relationship Links: BRENDA:EC:188.8.131.52 , BRENDA:EC:184.108.40.206 , BRENDA:EC:220.127.116.11 , ENZYME:EC:18.104.22.168 , ENZYME:EC:22.214.171.124 , ENZYME:EC:126.96.36.199 , IUBMB-ExplorEnz:EC:188.8.131.52 , IUBMB-ExplorEnz:EC:184.108.40.206 , IUBMB-ExplorEnz:EC:220.127.116.11 , UniProt:RELATED-TO:P07149 , UniProt:RELATED-TO:P12276 , UniProt:RELATED-TO:P12785 , UniProt:RELATED-TO:P49327
Heath96: Heath RJ, Rock CO (1996). "Roles of the FabA and FabZ beta-hydroxyacyl-acyl carrier protein dehydratases in Escherichia coli fatty acid biosynthesis." J Biol Chem 1996;271(44);27795-801. PMID: 8910376
Mizugaki68: Mizugaki M, Swindell AC, Wakil SJ (1968). "Intermediate- and long-chain beta-hydroxyacyl-ACP dehydrases from E. coli fatty acid synthetase." Biochem Biophys Res Commun 33(3);520-7. PMID: 4881058
Mohan94: Mohan S, Kelly TM, Eveland SS, Raetz CR, Anderson MS (1994). "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 1994;269(52);32896-903. PMID: 7806516
Sharma90: Sharma A, Henderson BS, Schwab JM, Smith JL (1990). "Crystallization and preliminary X-ray analysis of beta-hydroxydecanoyl thiol ester dehydrase from Escherichia coli." J Biol Chem 1990;265(9);5110-2. PMID: 2180957
Stoops79: Stoops JK, Ross P, Arslanian MJ, Aune KC, Wakil SJ, Oliver RM (1979). "Physicochemical studies of the rat liver and adipose fatty acid synthetases." J Biol Chem 254(15);7418-26. PMID: 457689
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