title: Identification and characterization of a novel yeast omega3-fatty acid desaturase acting on long-chain n-6 fatty acid substrates from Pichia pastoris.
abstract: A cDNA sequence putatively encoding a omega(3)-fatty acid desaturase gene was isolated from methylotrophic yeast Pichia pastoris GS115. The deduced amino acid sequence of this cloned cDNA showed high identity to known fungal omega(3)-fatty acid desaturases. Functional identification of this gene heterologously in Saccharomyces cerevisiae strain INVScl indicated that the deduced amino acid sequence exhibited omega(3)-fatty acid desaturase activity. The newly identified omega(3)-fatty acid desaturase, named Pp-FAD3, is novel because it showed broad n-6 fatty acid substrate specificity by its ability to convert all the 18-carbon and 20-carbon n-6 substrates examined to the corresponding n-3 fatty acids, with an approximately equivalent high conversion rate. Pp-FAD3 is the first known yeast omega(3)-fatty acid desaturase to act on long-chain n-6 fatty acid substrates. Heterologous expression of the newly identified omega(3) desaturase in different hosts will be an alternative method to increase the flow of n-6 fatty acid intermediates into their n-3 derivatives.
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Department of Microbiology, Nankai University, Tianjin 300071, People's Republic of China.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Zhang
authors.forename: Mingchun
authors.initials: M
authors.lastname: Li
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Wei
authors.forename: Laijun
authors.initials: L
authors.lastname: Xing
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D044943:Fatty Acid Desaturases / Q000235:genetics* / Q000378:metabolism; D043371:Fatty Acids, Omega-6 / Q000378:metabolism*; D008401:Gas Chromatography-Mass Spectrometry; D008969:Molecular Sequence Data; D010802:Phylogeny; D010843:Pichia / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D012331:RNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D013379:Substrate Specificity; D014170:Transformation, Genetic
chemical_list: D043371:Fatty Acids, Omega-6; D012331:RNA, Fungal; D044943:Fatty Acid Desaturases; C078565:omega-3 fatty acid desaturase