Saccharomyces kluyveri FAD3 encodes an omega3 fatty acid desaturase.
Fungi, like plants, are capable of producing the 18-carbon polyunsaturated fatty acids linoleic acid and alpha-linolenic acid. These fatty acids are synthesized by catalytic reactions of Delta12 and omega3 fatty acid desaturases. This paper describes the first cloning and functional characterization of a yeast omega3 fatty acid desaturase gene. The deduced protein encoded by the Saccharomyces kluyveri FAD3 gene (Sk-FAD3) consists of 419 amino acids, and shows 30-60 % identity with Delta12 fatty acid desaturases of several eukaryotic organisms and 29-31 % identity with omega3 fatty acid desaturases of animals and plants. During Sk-FAD3 expression in Saccharomyces cerevisiae, alpha-linolenic acid accumulated only when linoleic acid was added to the culture medium. The disruption of Sk-FAD3 led to the disappearance of alpha-linolenic acid in S. kluyveri. These findings suggest that Sk-FAD3 is the only omega3 fatty acid desaturase gene in this yeast. Furthermore, transcriptional expression of Sk-FAD3 appears to be regulated by low-temperature stress in a manner different from the other fatty acid desaturase genes in S. kluyveri.
Oura
Takahiro
T
Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8501, Japan.
Kajiwara
Susumu
S
Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Kanagawa 226-8501, Japan.
D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003470:Culture Media; D044943:Fatty Acid Desaturases / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D008401:Gas Chromatography-Mass Spectrometry; D008969:Molecular Sequence Data; D012440:Saccharomyces / Q000201:enzymology* / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000254:growth & development; D017422:Sequence Analysis, DNA; D014170:Transformation, Genetic
D003470:Culture Media; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D044943:Fatty Acid Desaturases