title: Metabolic engineering of omega-3 long-chain polyunsaturated fatty acids in plants using an acyl-CoA Delta6-desaturase with omega3-preference from the marine microalga Micromonas pusilla.
abstract: Long-chain (> or = C20) polyunsaturated fatty acids (LC-PUFA) EPA and DHA (20:5(Delta5,8,11,14,17) and 22:6(Delta4,7,10,13,16,19)) have well-documented health benefits against coronary heart disease, rheumatoid arthritis and other disorders. Currently, the predominant sources of these fatty acids are marine fish and algal oils, but research is being conducted to ensure that a sustainable, land-based production system can be developed. We here describe the metabolic engineering of an artificial pathway that produces 26% EPA in leaf triacylglycerol using a newly-identified Delta6-desaturase from the marine microalga Micromonas pusilla. We also demonstrate that this enzyme appears to function as an acyl-CoA desaturase that has preference for omega3 substrates both in planta and in yeast. Phylogenetic analysis indicates that this desaturase shares highly conserved motifs with previously described acyl-CoA Delta6-desaturases.
authors.affiliation: Food Futures National Research Flagship, CSIRO Plant Industry, PO Box 1600, Canberra, ACT 2601, Australia.
authors.forename: James R
authors.initials: JR
authors.lastname: Petrie
authors.forename: Pushkar
authors.initials: P
authors.lastname: Shrestha
authors.forename: Maged P
authors.initials: MP
authors.lastname: Mansour
authors.forename: Peter D
authors.initials: PD
authors.lastname: Nichols
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.forename: Surinder P
authors.initials: SP
authors.lastname: Singh
mesh_terms: D000818:Animals; D001669:Biochemical Phenomena; D000460:Chlorophyta / Q000235:genetics / Q000378:metabolism; D004281:Docosahexaenoic Acids / Q000378:metabolism; D056890:Eukaryota / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000235:genetics* / Q000378:metabolism*; D005227:Fatty Acids / Q000235:genetics / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000235:genetics / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D005399:Fishes / Q000235:genetics / Q000378:metabolism; D010944:Plants / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D013230:Stearoyl-CoA Desaturase / Q000235:genetics / Q000378:metabolism
chemical_list: D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D005231:Fatty Acids, Unsaturated; D004281:Docosahexaenoic Acids; D044943:Fatty Acid Desaturases; D013230:Stearoyl-CoA Desaturase