Identification of Δ5-Desaturase from Mortierella alpina by Heterologous Expression in Bakers’ Yeast and Canola

A DNA fragment with homology to Δ6-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 Δ6-desaturase genes. This fragment was used as a probe to...

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Bibliographic Details
Published in:The Journal of biological chemistry 1998-11, Vol.273 (45), p.29360
Main Authors: Deborah S. Knutzon, Jennifer M. Thurmond, Yung-Sheng Huang, Sunita Chaudhary, Emil G. Bobik, Jr, George M. Chan, Stephen J. Kirchner, Pradip Mukerji
Format: Article
Language:English
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Summary:A DNA fragment with homology to Δ6-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 Δ6-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 Δ5-desaturase activity. The effects of growth and induction conditions as well as host strain on activity of the recombinant Δ5-desaturase in S. cerevisiae were evaluated. Expression of the M. alpina Δ5-desaturase cDNA in transgenic canola seeds resulted in the production of taxoleic acid (Δ5,9–18:2) and pinolenic acid (Δ5,9,12–18:3), which are the Δ5-desaturation products of oleic and linoleic acids, respectively.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.273.45.29360