A gene （NANOC-D6D） encoding a desaturase that removes two hydrogen atoms from fatty acids at delta 6 position was isolated from a cDNA library of Nannochloropsis oculata （Droop） D. J. Hibberd （Eustigmatophyceae）...A gene （NANOC-D6D） encoding a desaturase that removes two hydrogen atoms from fatty acids at delta 6 position was isolated from a cDNA library of Nannochloropsis oculata （Droop） D. J. Hibberd （Eustigmatophyceae）. The unicellular marine microalga N. oculata synthesizes rich long chain polyunsaturated fatty acids （LCPUFAs）, including eicosapentaenoic acid （20：5n-3, EPA）. The deduced protein contains 474 amino acids that fold into 4 trans-membrane domains. The neighbor-joining phylogenetic tree indicates that NANOC-D6D is phylogenetically close to the delta-6 fatty acid desaturase of marine microalgae such as Glossomastix chrysoplasta, Thalassiosira pseudonana, and Phaeodactylum tricornutum. The gene was expressed in Saccharomyces cerevisiae INVScl to verify the substrate specificity of NAN OC-D6D. Our results suggest that the recombinant NANOC-D6D simultaneously desaturates linoleic acid （LA） and a-linolenic acid （ALA）.展开更多
基金Supported by the National Key Technology R&D Program in the 11th Five-Year Plan of China (No. 2006BAD09A03-2)the National High-tech Research and Development Program of China(863 Program) (No. 2007AA09Z427)
文摘A gene （NANOC-D6D） encoding a desaturase that removes two hydrogen atoms from fatty acids at delta 6 position was isolated from a cDNA library of Nannochloropsis oculata （Droop） D. J. Hibberd （Eustigmatophyceae）. The unicellular marine microalga N. oculata synthesizes rich long chain polyunsaturated fatty acids （LCPUFAs）, including eicosapentaenoic acid （20：5n-3, EPA）. The deduced protein contains 474 amino acids that fold into 4 trans-membrane domains. The neighbor-joining phylogenetic tree indicates that NANOC-D6D is phylogenetically close to the delta-6 fatty acid desaturase of marine microalgae such as Glossomastix chrysoplasta, Thalassiosira pseudonana, and Phaeodactylum tricornutum. The gene was expressed in Saccharomyces cerevisiae INVScl to verify the substrate specificity of NAN OC-D6D. Our results suggest that the recombinant NANOC-D6D simultaneously desaturates linoleic acid （LA） and a-linolenic acid （ALA）.
