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Cloning and Heterologous Expression of Δ5 Desaturase Gene from Mortiella alpina

LIU Jian-min1,2,LI Mao-teng1,*   

  1. 1. College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China;
    2. Institute of Resources and Environment, Henan Polytechnic University, Jiaozuo 454000, China
  • Online:2013-08-15 Published:2013-09-03
  • Contact: LI Mao-teng

Abstract:

Arachidonic acid, an essential fatty acid for humans, plays important physiological functions in the intelligence
development and vision development of infants. In this study, a complete Δ5 desaturase gene was cloned from Mortierella
alpina W15 by RT-PCR amplification. The gene with 1341 bp in length encoded 446 amino acids. The deduced amino acid
sequence demonstrated the cytochrome b5 domain in the N terminal and three conserved histidine boxes in the sequence.
Then the gene was inserted into the expression vector pPIC3.5K and transformed into Pichia pastoris GS115. Transformants
containing multi-copy Δ5 desaturase genes were screened by Geneticin (G418). When dihomo-γ-linolenic acid was provided
as the exogenous substrate to the culture induced by methanol, the dehydrogenation of the substrate was catalyzed by Δ5
desaturase to produce arachidonic acid reaching 2.85% in the total fatty acids. This result indicated that the cloned gene
encoded functional Δ5 desaturase in P. pastoris GS115.

Key words: Mortierella alpina;&Delta, 5 desaturase gene;Pichia pastoris GS115;arachidonic acid

CLC Number: