title: Caenorhabditis elegans Delta12-desaturase FAT-2 is a bifunctional desaturase able to desaturate a diverse range of fatty acid substrates at the Delta12 and Delta15 positions.
abstract: Caenorhabditis elegans FAT-2 has been characterized as fatty acid Δ12-desaturase able to desaturate C16 and C18 fatty acids. However, in this report we show that when expressed in yeast cells this enzyme can also catalyze Δ15 desaturation. This results in the production of both linoleic acid (ω6 C18:2Δ9,12) and linolenic acid (ω3 C18:3Δ9,12,15) from oleic acid (C18:1Δ9) substrate, and hexadecadienoic acid (ω4 C16:2Δ9,12) and hexadecatrienoic acid (ω1 C16:3Δ9,12,15) from palmitoleic acid (C16:1Δ9) substrate. In addition, this enzyme can also produce C14:2Δ9,12, C15:2Δ9,12, C17:2Δ9,12, and C18:4Δ6,9,12,15 when C14:1Δ9, C15:1Δ9, C17:1Δ9, and C18:3Δ6,9,12 substrates are available in yeast cells. Mass spectrometry analysis of 2,4-dimethyloxazoline modification of fatty acid methyl esters confirms the positions of all newly formed double bonds. These results indicate that when expressed in yeast the C. elegans Δ12-desaturase CeFAT-2 shows a characteristic of a bifunctional Δ12/Δ15-desaturase and has a great deal of elasticity with respect to fatty acid chain length in being able to accept fatty acids ranging from C14 to C18. Interestingly, despite possessing a bifunctional Δ12/Δ15 desaturation activity, phylogenetic analysis suggests that C. elegans Δ12-desaturase CeFAT-2 might have arisen independently from other reported dual Δ12/Δ15-desaturases from fungi and protozoa.
authors: Commonwealth Scientific and Industrial Research Organisation Plant Industry, G.P.O. Box 1600, Canberra, Australian Capital Territory 2601, Australia. Electronic address: xue-rong.zhou@csiro.au.
authors: Xue-Rong
authors: XR
authors: Zhou
authors: Commonwealth Scientific and Industrial Research Organisation Plant Industry, G.P.O. Box 1600, Canberra, Australian Capital Territory 2601, Australia.
authors: Allan G
authors: AG
authors: Green
authors: Commonwealth Scientific and Industrial Research Organisation Plant Industry, G.P.O. Box 1600, Canberra, Australian Capital Territory 2601, Australia.
authors: Surinder P
authors: SP
authors: Singh
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D002849:Chromatography, Gas / Q000379:methods; D003001:Cloning, Molecular; D044943:Fatty Acid Desaturases / Q000378:metabolism*; D005227:Fatty Acids / Q000737:chemistry; D005229:Fatty Acids, Monounsaturated / Q000737:chemistry; D005231:Fatty Acids, Unsaturated / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D005786:Gene Expression Regulation; D019787:Linoleic Acid / Q000737:chemistry; D050356:Lipid Metabolism; D008957:Models, Genetic; D019301:Oleic Acid / Q000737:chemistry; D010802:Phylogeny; D011485:Protein Binding
chemical_list: D029742:Caenorhabditis elegans Proteins; D005227:Fatty Acids; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; C492490:fat-2 protein, C elegans; C008757:palmitoleic acid; D019301:Oleic Acid; D019787:Linoleic Acid; D044943:Fatty Acid Desaturases; C040448:delta-12 fatty acid desaturase