MetaCyc Reaction: 1.14.19.j

Superclasses: Reactions Classified By Conversion Type Simple Reactions Chemical Reactions
Reactions Classified By Substrate Small-Molecule Reactions

EC Number: 1.14.19.j

Enzymes and Genes:

Arabidopsis thaliana col : chloroplastic acyl-lipid ω-3 desaturase Inferred from experiment : FAD7
chloroplastic acyl-lipid ω-3 desaturase Inferred from experiment : FAD8

In Pathway: α-linolenate biosynthesis I (plants and red algae)

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. Please see the PGDB Concepts Guide for more information.

Mass balance status: Balanced.

Enzyme Commission Primary Name: sn-2 acyl-lipid ω-3 desaturase (ferredoxin)

Standard Gibbs Free Energy (ΔrG in kcal/mol): -56.57999 Inferred by computational analysis [Latendresse13]

Enzyme Commission Summary:
This plastidial enzyme desaturates 16:2 and 18:2 fatty acids to 16:3 and 18:3 fatty acids, respectively, on all 16:2- or 18:2-containing chloroplast membrane lipids, including phosphatidylglycerol, monogalactosyldiacylglycerol, digalactosyldiaclyglycerol, and sulfoguinovosyldiacylglycerol. The enzyme introduces a cis double bond at a location 3 carbons away from the methyl end of the fatty acid. The distance from the carboxylic acid end of the molecule does not affect the location of the new double bond. cf EC 1.14.19.m, acyl-lipid ω-3 desaturase (cytochrome b5) and EC 1.14.19.t, sn-1 acyl-lipid ω-3 desaturase (ferredoxin).

Citations: [Iba93, McConn94, VenegasCaleron06]

Gene-Reaction Schematic: ?

Gene-Reaction Schematic


Iba93: Iba K, Gibson S, Nishiuchi T, Fuse T, Nishimura M, Arondel V, Hugly S, Somerville C (1993). "A gene encoding a chloroplast omega-3 fatty acid desaturase complements alterations in fatty acid desaturation and chloroplast copy number of the fad7 mutant of Arabidopsis thaliana." J Biol Chem 1993;268(32);24099-105. PMID: 8226956

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

McConn94: McConn M, Hugly S, Browse J, Somerville C (1994). "A Mutation at the fad8 Locus of Arabidopsis Identifies a Second Chloroplast [omega]-3 Desaturase." Plant Physiol 106(4);1609-1614. PMID: 12232435

VenegasCaleron06: Venegas-Caleron M, Muro-Pastor AM, Garces R, Martinez-Force E (2006). "Functional characterization of a plastidial omega-3 desaturase from sunflower (Helianthus annuus) in cyanobacteria." Plant Physiol Biochem 44(10);517-25. PMID: 17064923

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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 Fri Oct 9, 2015, biocyc13.