title: Identification of Delta5-desaturase from Mortierella alpina by heterologous expression in Bakers' yeast and canola.
abstract: A DNA fragment with homology to Delta6-desaturases from borage and cyanobacteria was isolated after polymerase chain reaction amplification of Mortierella alpina cDNA with oligonucleotide primers corresponding to the conserved regions of known Delta6-desaturase genes. This fragment was used as a probe to isolate a cDNA clone with an open reading frame encoding 446 amino acids from a M. alpina library. Expression of this open reading frame from an inducible promoter in Saccharomyces cerevisiae in the presence of various substrates revealed that the recombinant product had Delta5-desaturase activity. The effects of growth and induction conditions as well as host strain on activity of the recombinant Delta5-desaturase in S. cerevisiae were evaluated. Expression of the M. alpina Delta5-desaturase cDNA in transgenic canola seeds resulted in the production of taxoleic acid (Delta5,9-18:2) and pinolenic acid (Delta5,9,12-18:3), which are the Delta5-desaturation products of oleic and linoleic acids, respectively.
authors.affiliation: Calgene, LLC, Davis, California 95616, USA.
authors.forename: D S
authors.initials: DS
authors.lastname: Knutzon
authors.forename: J M
authors.initials: JM
authors.lastname: Thurmond
authors.forename: Y S
authors.initials: YS
authors.lastname: Huang
authors.forename: S
authors.initials: S
authors.lastname: Chaudhary
authors.forename: E G
authors.initials: EG
authors.lastname: Bobik
authors.forename: G M
authors.initials: GM
authors.lastname: Chan
authors.forename: S J
authors.initials: SJ
authors.lastname: Kirchner
authors.forename: P
authors.initials: P
authors.lastname: Mukerji
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary; D044943:Fatty Acid Desaturases / Q000235:genetics / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D008969:Molecular Sequence Data; D020094:Mortierella / Q000201:enzymology*; D030821:Plants, Genetically Modified; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D012639:Seeds / Q000235:genetics; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D011994:Recombinant Proteins; D044943:Fatty Acid Desaturases; C094563:delta-15 desaturase