title: Isolation and characterisation of a high-efficiency desaturase and elongases from microalgae for transgenic LC-PUFA production.
abstract: The production of long-chain polyunsaturated fatty acids from precursor molecules linoleic acid (LA; 18:2omega6) and alpha-linolenic acid (ALA; 18:3omega3) is catalysed by sequential desaturase and elongase reactions. We report the isolation of a front-end Delta6-desaturase gene from the microalgae Ostreococcus lucimarinus and two elongase genes, a Delta6-elongase and a Delta5-elongase, from the microalga Pyramimonas cordata. These enzymes efficiently convert their respective substrates when transformed in yeast (39-75% conversion for omega3 substrate fatty acids), and the Delta5-elongase in particular displays higher elongation efficiency (75% for conversion of eicosapentaenoic acid (20:5omega3) to docosapentaenoic acid (22:5omega3)) than previously reported genes. In addition, the Delta6-desaturase is homologous with acyl-CoA desaturases and shows a strong preference for the omega3 substrate ALA.
authors.affiliation: Food Futures National Research Flagship, CSIRO Plant Industry, P. O. Box 1600, Canberra, ACT 2601, Australia.
authors.forename: James R
authors.initials: JR
authors.lastname: Petrie
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.forename: Anne M
authors.initials: AM
authors.lastname: Mackenzie
authors.forename: Pushkar
authors.initials: P
authors.lastname: Shrestha
authors.forename: Maged P
authors.initials: MP
authors.lastname: Mansour
authors.forename: Stan S
authors.initials: SS
authors.lastname: Robert
authors.forename: Dion F
authors.initials: DF
authors.lastname: Frampton
authors.forename: Susan I
authors.initials: SI
authors.lastname: Blackburn
authors.forename: Peter D
authors.initials: PD
authors.lastname: Nichols
authors.forename: Surinder P
authors.initials: SP
authors.lastname: Singh
mesh_terms: D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000460:Chlorophyta / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D044943:Fatty Acid Desaturases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis / Q000235:genetics; D058086:Microalgae / Q000145:classification / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D019076:Transgenes / Q000235:genetics
chemical_list: D005231:Fatty Acids, Unsaturated; D010940:Plant Proteins; D044943:Fatty Acid Desaturases; D000123:Acetyltransferases