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MetaCyc Pathway: Δ5-eicosenoate biosynthesis

Enzyme View:

Pathway diagram: delta5-eicosenoate biosynthesis

This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Synonyms: Δ5-eicosenoic acid biosynthesis

Superclasses: Biosynthesis Fatty Acid and Lipid Biosynthesis Fatty Acid Biosynthesis Unsaturated Fatty Acid Biosynthesis

Some taxa known to possess this pathway include ? : Limnanthes alba , Limnanthes douglasii

Expected Taxonomic Range: Magnoliophyta

Summary:
Oleate (18:1Δ9) is the most commonly found mono-unsaturated fatty acids in plant oils. However a number of other mono-unsaturated fatty acid species are naturally accumulated in some plants. The seed oil of Limnanthes alba (meadowfoam) has high content of Δ5 unsaturated C20 and C22 fatty acids, with (5Z)-icos-5-enoate (20:1Δ5) accounting for 60% of the total fatty acids. The high content of (5Z)-icos-5-enoate makes the meadowfoam seed oil desirable for use in cosmetics, surfactants and lubricants.

The biosynthesis of Δ5-eicosenoate biosynthesis in Limnanthes alba has several novel features. Firstly, the elongation step, which is catalyzed by saturated fatty acid-specific FAE1, starts with palmitate (16:0) instead of stearate (18:0) or oleate (18:1). The latter two serve as the initial substrates for very long chain fatty acids biosynthesis in most plant species [Pollard80].

Secondly, the Δ5 double bond is introduced by an acyl-CoA desaturase [Moreau81, Cahoon00]. Acyl-CoA desaturation is the major route of monounsaturated fatty acid synthesis in animals and fungi, but is rarely found in plants, which usually use either an acyl-[acp] desaturase or an acyl-lipid desaturase (which act on fatty acids bound to coenzyme A or glycerol lipids, respectively, as substrates).

Variants: cis-dodecenoate biosynthesis , cis-vaccenate biosynthesis , sapienate biosynthesis

Credits:
Created 02-Oct-2006 by Zhang P , TAIR
Revised 12-Nov-2014 by Caspi R , SRI International


References

Cahoon00: Cahoon EB, Marillia EF, Stecca KL, Hall SE, Taylor DC, Kinney AJ (2000). "Production of fatty acid components of meadowfoam oil in somatic soybean embryos." Plant Physiol 124(1);243-51. PMID: 10982439

Moreau81: Moreau RA, Pollard MR, Stumpf PK (1981). "Properties of a delta 5-fatty acyl-CoA desaturase in the cotyledons of developing Limnanthes alba." Arch Biochem Biophys 209(2);376-84. PMID: 7294800

Pollard80: Pollard MR, Stumpf PK (1980). "Biosynthesis of C(20) and C(22) Fatty Acids by Developing Seeds of Limnanthes alba: CHAIN ELONGATION AND Delta5 DESATURATION." Plant Physiol 66(4);649-55. PMID: 16661496

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

King, 2007: King A, Nam JW, Han J, Hilliard J, Jaworski JG (2007). "Cuticular wax biosynthesis in petunia petals: cloning and characterization of an alcohol-acyltransferase that synthesizes wax-esters." Planta 226(2);381-94. PMID: 17323080

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Lederer94: Lederer F (1994). "The cytochrome b5-fold: an adaptable module." Biochimie 76(7);674-92. PMID: 7893819

Napier03: Napier JA, Michaelson LV, Sayanova O (2003). "The role of cytochrome b5 fusion desaturases in the synthesis of polyunsaturated fatty acids." Prostaglandins Leukot Essent Fatty Acids 68(2);135-43. PMID: 12538077


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.0 on Sat Mar 28, 2015, BIOCYC13B.