MetaCyc Reaction:

Superclasses: Reactions Classified By Conversion TypeSimple ReactionsChemical Reactions
Reactions Classified By SubstrateSmall-Molecule Reactions

EC Number:

Enzymes and Genes:

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

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

The direction shown, i.e. which substrates are on the left and right sides, 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. 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): -56.57999Inferred by computational analysis [Latendresse13]

Enzyme Commission Summary:
This plastidial enzyme desaturates 16:2 fatty acids attached to the sn-2 position of glycerolipids to 16:3 fatty acids, and converts18:2 to 18:3 in both the sn-1 and sn-2 positions. It acts on all 16:2- or 18:2-containing chloroplast membrane lipids, including phosphatidylglycerol, monogalactosyldiacylglycerol, digalactosyldiaclyglycerol, and sulfoquinovosyldiacylglycerol. 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, acyl-lipid ω-3 desaturase (cytochrome b5) and EC, sn-1 acyl-lipid ω-3 desaturase (ferredoxin).

Citations: [Iba93, McConn94, VenegasCaleron06]

Gene-Reaction Schematic

Gene-Reaction Schematic

Relationship Links: BRENDA:EC:, ENZYME:EC:, IUBMB-ExplorEnz:EC:


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

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
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