Accepted name: acyl-[acyl-carrier-protein] 4-desaturase
Reaction: palmitoyl-[acyl-carrier protein] + 2 reduced ferredoxin [iron-sulfur] cluster + O2 + 2 H+ = (4Z)-hexadec-4-enoyl-[acyl-carrier protein] + 2 oxidized ferredoxin [iron-sulfur] cluster + 2 H2O
Other name(s): Δ4-palmitoyl-[acyl carrier protein] desaturase
Systematic name: palmitoyl-[acyl-carrier protein],reduced acceptor:oxygen oxidoreductase (4,5 cis-dehydrogenating)
Comments: The enzymes from the plants Coriandrum sativum (coriander) and Hedera helix (English ivy) are involved in biosynthesis of petroselinate [(6Z)-octadec-6-enoate], which is formed by elongation of (4Z)-hexadec-4-enoate. The ivy enzyme can also act on oleoyl-[acyl-carrier protein] and palmitoleoyl-[acyl-carrier protein], generating the corresponding 4,9-diene.
1.  Cahoon, E.B., Shanklin, J. and Ohlrogge, J.B. Expression of a coriander desaturase results in petroselinic acid production in transgenic tobacco. Proc. Natl. Acad. Sci. USA 89 (1992) 11184–11188. [PMID: 1454797]
2.  Cahoon, E.B. and Ohlrogge, J.B. Metabolic evidence for the involvement of a Δ4-palmitoyl-acyl carrier protein desaturase in petroselinic acid synthesis in coriander endosperm and transgenic tobacco cells. Plant Physiol. 104 (1994) 827–837. [PMID: 12232129]
3.  Whittle, E., Cahoon, E.B., Subrahmanyam, S. and Shanklin, J. A multifunctional acyl-acyl carrier protein desaturase from Hedera helix L. (English ivy) can synthesize 16- and 18-carbon monoene and diene products. J. Biol. Chem. 280 (2005) 28169–28176. [PMID: 15939740]
[EC created 2015]
Accepted name: β-ketoacyl-[acyl-carrier-protein] synthase II
Reaction: a (Z)-hexadec-9-enoyl-[acyl-carrier protein] + a malonyl-[acyl-carrier protein] = a (Z)-3-oxooctadec-11-enoyl-[acyl-carrier protein] + CO2 + an [acyl-carrier protein]
Glossary: palmitoleoyl-[acyl-carrier protein] = (Z)-hexadec-9-enoyl-[acyl-carrier protein]
cis-vaccenoyl-[acyl-carrier protein] = (Z)-octadec-11-enoyl-[acyl-carrier protein]
Other name(s): KASII; KAS II; FabF; 3-oxoacyl-acyl carrier protein synthase II; β-ketoacyl-ACP synthase II
Systematic name: (Z)-hexadec-9-enoyl-[acyl-carrier protein]:malonyl-[acyl-carrier protein] C-acyltransferase (decarboxylating)
Comments: Involved in the dissociated (or type II) fatty acid biosynthesis system that occurs in plants and bacteria. While the substrate specificity of this enzyme is very similar to that of EC, β-ketoacyl-[acyl-carrier-protein] synthase I, it differs in that palmitoleoyl-[acyl-carrier protein] is not a good substrate of EC but is an excellent substrate of this enzyme [1,2]. The fatty-acid composition of Escherichia coli changes as a function of growth temperature, with the proportion of unsaturated fatty acids increasing with lower growth temperature. This enzyme controls the temperature-dependent regulation of fatty-acid composition, with mutants lacking this acivity being deficient in the elongation of palmitoleate to cis-vaccenate at low temperatures [3,4].
1.  D'Agnolo, G., Rosenfeld, I.S. and Vagelos, P.R. Multiple forms of β-ketoacyl-acyl carrier protein synthetase in Escherichia coli. J. Biol. Chem. 250 (1975) 5289–5294. [PMID: 237914]
2.  Garwin, J.L., Klages, A.L. and Cronan, J.E., Jr.. Structural, enzymatic, and genetic studies of β-ketoacyl-acyl carrier protein synthases I and II of Escherichia coli. J. Biol. Chem. 255 (1980) 11949–11956. [PMID: 7002930]
3.  Price, A.C., Rock, C.O. and White, S.W. The 1.3-Angstrom-resolution crystal structure of β-ketoacyl-acyl carrier protein synthase II from Streptococcus pneumoniae. J. Bacteriol. 185 (2003) 4136–4143. [PMID: 12837788]
4.  Garwin, J.L., Klages, A.L. and Cronan, J.E., Jr. β-Ketoacyl-acyl carrier protein synthase II of Escherichia coli. Evidence for function in the thermal regulation of fatty acid synthesis. J. Biol. Chem. 255 (1980) 3263–3265. [PMID: 6988423]
5.  Magnuson, K., Carey, M.R. and Cronan, J.E., Jr. The putative fabJ gene of Escherichia coli fatty acid synthesis is the fabF gene. J. Bacteriol. 177 (1995) 3593–3595. [PMID: 7768872]
6.  Cronan, J.E., Jr. and Rock, C.O. Biosynthesis of membrane lipids. In: Neidhardt, F.C. (Ed.), Escherichia coli and Salmonella: Cellular and Molecular Biology, 2nd edn, vol. 1, ASM Press, Washington, DC, 1996, pp. 612–636.
[EC created 2006, modified 2020]
Accepted name: Kdo2-lipid IVA palmitoleoyltransferase
Reaction: a (9Z)-hexadec-9-enoyl-[acyl-carrier protein] + Kdo2-lipid IVA = (9Z)-hexadec-9-enoyl-Kdo2-lipid IVA + an [acyl-carrier protein]
Glossary: Kdo = 3-deoxy-D-manno-oct-2-ulopyranosylonic acid
lipid IVA = 2-deoxy-2-[(3R)-3-hydroxytetradecanamido]-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl phosphate
Kdo2-lipid IVA = α-Kdo-(2→4)-α-Kdo-(2→6)-lipid IVA
(9Z)-hexadec-9-enoyl = palmitoleoyl
(9Z)-hexadec-9-enoyl-Kdo2-lipid IVA = α-Kdo-(2→4)-α-Kdo-(2→6)-2-deoxy-2-{(3R)-3-[(9Z)-hexadec-9-enoyl]tetradecanamido}-3-O-[(3R)-3-hydroxytetradecanoyl]-4-O-phospho-β-D-glucopyranosyl-(1→6)-2-deoxy-3-O-[(3R)-3-hydroxytetradecanoyl]-2-[(3R)-3-hydroxytetradecanamido]-α-D-glucopyranosyl phosphate
Other name(s): LpxP; palmitoleoyl-acyl carrier protein-dependent acyltransferase; cold-induced palmitoleoyl transferase; palmitoleoyl-[acyl-carrier protein]:Kdo2-lipid IVA O-palmitoleoyltransferase; (Kdo)2-lipid IVA palmitoleoyltransferase; α-Kdo-(2→4)-α-(2→6)-lipid IVA palmitoleoyltransferase
Systematic name: (9Z)-hexadec-9-enoyl-[acyl-carrier protein]:Kdo2-lipid IVA O-palmitoleoyltransferase
Comments: The enzyme, characterized from the bacterium Escherichia coli, is induced upon cold shock and is involved in the formation of a cold-adapted variant of the outer membrane glycolipid lipid A.
1.  Carty, S.M., Sreekumar, K.R. and Raetz, C.R. Effect of cold shock on lipid A biosynthesis in Escherichia coli. Induction At 12 degrees C of an acyltransferase specific for palmitoleoyl-acyl carrier protein. J. Biol. Chem. 274 (1999) 9677–9685. [PMID: 10092655]
2.  Vorachek-Warren, M.K., Carty, S.M., Lin, S., Cotter, R.J. and Raetz, C.R. An Escherichia coli mutant lacking the cold shock-induced palmitoleoyltransferase of lipid A biosynthesis: absence of unsaturated acyl chains and antibiotic hypersensitivity at 12 degrees C. J. Biol. Chem. 277 (2002) 14186–14193. [PMID: 11830594]
[EC created 2014]