Escherichia coli K-12 substr. MG1655 Pathway: palmitoleate biosynthesis I (from (5Z)-dodec-5-enoate)

Pathway diagram: palmitoleate biosynthesis I (from (5Z)-dodec-5-enoate)

If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Locations of Mapped Genes:

Schematic showing all replicons, marked with selected genes

Genetic Regulation Schematic

Genetic regulation schematic for palmitoleate biosynthesis I (from (5Z)-dodec-5-enoate)

Synonyms: palmitoleic acid biosynthesis I, palmitoleate biosynthesis (anaerobic)

Superclasses: BiosynthesisFatty Acid and Lipid BiosynthesisFatty Acid BiosynthesisUnsaturated Fatty Acid BiosynthesisPalmitoleate Biosynthesis

General Background

Palmitoleate is a common unsaturated fatty acid, found in bacteria, fungi [Casey94], plants [Gibson93] and animals [Goeransson65, Keith67].

In E. coli, two unsaturated fatty acids, palmitoleate and cis-vaccenate, together comprise about one-half of the total fatty acid content of the organism. Palmitate, palmitoleate and cis-vaccenate make up the bulk of the fatty acids found in E. coli membranes [Magnuson93].

About This Pathway

E. coli has three β-ketoacyl-ACP synthases (KAS): KASI, KASII and KASIII, encoded by fabB, fabF and fabH, respectively.

In E. coli, the extension of a cis-δ-5-decenoyl-[acp] to a palmitoleoyl-[acp] is believed to be catalyzed primarily by KASI. Inactivation of this enzyme leads to a lack of unsaturated fatty acids [Cronan69]. On the other hand, overexpression of KASI leads to the overproduction of cis-vaccenate [deMendoza83].

It has been shown that the basal ratio of saturated to unsaturated fatty acids in E. coli is controlled by the level of two enzymes - β-hydroxyacyl-ACP dehydratase/isomerase ( fabA) and KASI [Magnuson93]. The former introduces unsaturation (see (5Z)-dodec-5-enoate biosynthesis), while the other elongates the unsaturated fatty acid to the level of a palmitoleoyl-[acp] (this pathway).

Additional control over this ratio is provided by temperature. The proportion of unsaturated fatty acids is known to increase in E. coli with lower growth temperature, a phenomenon found in most organisms that provides a mechanism for adjusting the lipid phase transition of the membrane phospholipids to differing temperatures. It has been shown that KASII which is responsible for the further elongation of the unsaturated fatty acids to the final level of cis-vaccenate (see cis-vaccenate biosynthesis), is more active at low temperatures (relative to the overall rate of fatty acid synthesis) than at high temperatures [Garwin80]. This relative increase results in the production of cis-vaccenate rather than palmitoleate. Because the former (but not the later) can be incorporated into both positions of sn-glycerol 3-phosphate, the synthesis of di-unsaturated phospholipids occurs and the thermotrophic phase transition of the membrane phospholipids is lowered [Garwin80a].

Superpathways: superpathway of unsaturated fatty acids biosynthesis (E. coli)

Created 24-Jun-2009 by Caspi R, SRI International


Casey94: Casey WM, Gibson KJ, Parks LW (1994). "Covalent attachment of palmitoleic acid (C16:1 delta 9) to proteins in Saccharomyces cerevisiae. Evidence for a third class of acylated proteins." J Biol Chem 269(3);2082-5. PMID: 8294460

Cronan69: Cronan JE, Birge CH, Vagelos PR (1969). "Evidence for two genes specifically involved in unsaturated fatty acid biosynthesis in Escherichia coli." J Bacteriol 100(2);601-4. PMID: 4901354

deMendoza83: de Mendoza D, Klages Ulrich A, Cronan JE (1983). "Thermal regulation of membrane fluidity in Escherichia coli. Effects of overproduction of beta-ketoacyl-acyl carrier protein synthase I." J Biol Chem 258(4);2098-101. PMID: 6337151

Garwin80: Garwin JL, Klages AL, Cronan JE (1980). "Structural, enzymatic, and genetic studies of beta-ketoacyl-acyl carrier protein synthases I and II of Escherichia coli." J Biol Chem 1980;255(24);11949-56. PMID: 7002930

Garwin80a: Garwin JL, Klages AL, Cronan JE (1980). "Beta-ketoacyl-acyl carrier protein synthase II of Escherichia coli. Evidence for function in the thermal regulation of fatty acid synthesis." J Biol Chem 1980;255(8);3263-5. PMID: 6988423

Gibson93: Gibson KJ (1993). "Palmitoleate formation by soybean stearoyl-acyl carrier protein desaturase." Biochim Biophys Acta 1169(3);231-5. PMID: 7548115

Goeransson65: Goeransson G (1965). "The metabolism of fatty acids in the rat. V. palmitoleic acid." Acta Physiol Scand 63;428-33. PMID: 14321753

Keith67: Keith AD (1967). "Fatty acid metabolism in D. melanogaster: formation of palmitoleate." Life Sci 6(2);213-8. PMID: 6030882

Magnuson93: Magnuson K, Jackowski S, Rock CO, Cronan JE (1993). "Regulation of fatty acid biosynthesis in Escherichia coli." Microbiol Rev 1993;57(3);522-42. PMID: 8246839

Other References Related to Enzymes, Genes, Subpathways, and Substrates of this Pathway

Baldock96: Baldock C, Rafferty JB, Sedelnikova SE, Baker PJ, Stuitje AR, Slabas AR, Hawkes TR, Rice DW (1996). "A mechanism of drug action revealed by structural studies of enoyl reductase." Science 274(5295);2107-10. PMID: 8953047

Barnes68: Barnes EM, Wakil SJ (1968). "Studies on the mechanism of fatty acid synthesis. XIX. Preparation and general properties of palmityl thioesterase." J Biol Chem 1968;243(11);2955-62. PMID: 4871199

Bergler92: Bergler H, Hogenauer G, Turnowsky F (1992). "Sequences of the envM gene and of two mutated alleles in Escherichia coli." J Gen Microbiol 1992;138 ( Pt 10);2093-100. PMID: 1364817

Bergler94: Bergler H, Wallner P, Ebeling A, Leitinger B, Fuchsbichler S, Aschauer H, Kollenz G, Hogenauer G, Turnowsky F (1994). "Protein EnvM is the NADH-dependent enoyl-ACP reductase (FabI) of Escherichia coli." J Biol Chem 1994;269(8);5493-6. PMID: 8119879

Bergler96: Bergler H, Fuchsbichler S, Hogenauer G, Turnowsky F (1996). "The enoyl-[acyl-carrier-protein] reductase (FabI) of Escherichia coli, which catalyzes a key regulatory step in fatty acid biosynthesis, accepts NADH and NADPH as cofactors and is inhibited by palmitoyl-CoA." Eur J Biochem 242(3);689-94. PMID: 9022698

Bonner72: Bonner WM, Bloch K (1972). "Purification and properties of fatty acyl thioesterase I from Escherichia coli." J Biol Chem 1972;247(10);3123-33. PMID: 4554913

Byers07: Byers DM, Gong H (2007). "Acyl carrier protein: structure-function relationships in a conserved multifunctional protein family." Biochem Cell Biol 85(6);649-62. PMID: 18059524

Campbell01a: Campbell JW, Cronan JE (2001). "Bacterial fatty acid biosynthesis: targets for antibacterial drug discovery." Annu Rev Microbiol 55;305-32. PMID: 11544358

Cao10: Cao Y, Yang J, Xian M, Xu X, Liu W (2010). "Increasing unsaturated fatty acid contents in Escherichia coli by coexpression of three different genes." Appl Microbiol Biotechnol 87(1);271-80. PMID: 20135119

Chan10a: Chan DI, Vogel HJ (2010). "Current understanding of fatty acid biosynthesis and the acyl carrier protein." Biochem J 430(1);1-19. PMID: 20662770

Cho94: Cho H, Cronan JE (1994). ""Protease I" of Escherichia coli functions as a thioesterase in vivo." J Bacteriol 176(6);1793-5. PMID: 8132479

Cho95: Cho H, Cronan JE (1995). "Defective export of a periplasmic enzyme disrupts regulation of fatty acid synthesis." J Biol Chem 270(9);4216-9. PMID: 7876180

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

ECOSAL: "Escherichia coli and Salmonella: Cellular and Molecular Biology." Online edition.

Escaich11: Escaich S, Prouvensier L, Saccomani M, Durant L, Oxoby M, Gerusz V, Moreau F, Vongsouthi V, Maher K, Morrissey I, Soulama-Mouze C (2011). "The MUT056399 inhibitor of FabI is a new antistaphylococcal compound." Antimicrob Agents Chemother 55(10);4692-7. PMID: 21825292

Feng09: Feng Y, Cronan JE (2009). "Escherichia coli unsaturated fatty acid synthesis: complex transcription of the fabA gene and in vivo identification of the essential reaction catalyzed by FabB." J Biol Chem 284(43);29526-35. PMID: 19679654

GOA01: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

GOA01a: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA06: GOA, SIB (2006). "Electronic Gene Ontology annotations created by transferring manual GO annotations between orthologous microbial proteins."

Goh09: Goh S, Boberek JM, Nakashima N, Stach J, Good L (2009). "Concurrent growth rate and transcript analyses reveal essential gene stringency in Escherichia coli." PLoS One 4(6);e6061. PMID: 19557168

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
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