Delta-4 desaturase and its use in making polyunsaturated fatty acids
AssigneeE.I. du Pont de Nemours and Company
InventorsQuinn Qun Zhu, Zhixiong Xue
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Abstract
Described here are Δ4 desaturases that convert all-cis-7,10,13,16,19-docosapentaenoic acid [“DPA”; 22:5 ω-3] to docosahexaenoic acid [“DHA”; 22:6 ω-3], with secondary activity in converting docosatetraenoic acid [“DTA”; 22:4 ω-6] to all-cis-4,7,10,13,16-docosapentaenoic acid [“DPAn-6”; 22:5 ω-6]. Also, described here are isolated nuclei acid fragments and recombinant constructs comprising such fragments encoding Δ4 desaturases as well as methods of making long chain polyunsaturated fatty acids [“PUFAs”] using this Δ4 desaturase in oleaginous yeast.
Claims17
An isolated nucleic acid molecule selected from the group consisting of:
- (a) an isolated nucleotide sequence encoding a Δ4 desaturase enzyme selected from the group consisting of SEQ ID NO:2 and SEQ ID NO:4;
- (b) an isolated nucleotide sequence that hybridizes with (a) under the following hybridization conditions:
- 0.1×SSC, 0.1% SDS, 65° C. and washed with 2×SSC, 0.1% SDS followed by 0.1×SSC, 0.1% SDS;
- and
- (c) an isolated nucleotide sequence that is completely complementary to (a) or (b).
An isolated nucleic acid molecule comprising a first nucleotide sequence encoding a Δ4 desaturase enzyme of at least 514 amino acids that has at least 68% identity based on the Clustal W method of alignment when compared to a polypeptide having the sequence as set forth in SEQ ID NO:2;
- or a second nucleotide sequence comprising the complement of the first nucleotide sequence.
A polypeptide encoding a Δ4 desaturase enzyme selected from the group consisting of SEQ ID NO:2 and SEQ ID NO:4.
A method of making a polyunsaturated fatty acid selected from the group consisting of docosahexaenoic acid and all-cis-4,7,10,13,16-docosapentaenoic acid (22:5, w-6), comprising:
- a) providing a host cell comprising:
- (i) an isolated nucleotide molecule encoding a Δ4 desaturase polypeptide having at least 68% identity when compared to a polypeptide having the amino acid sequence as set forth in SEQ ID NO:2, based on the Clustal W method of alignment;
- and,
- (ii) a source fatty acid selected from the group consisting of all-cis-7,10,13,16,19-docosapentaenoic acid (22:5, w-3) and docosatetraenoic acid;
- b) growing the host cell of step (a) under conditions to express the nucleic acid fragment encoding the Δ4 desaturase polypeptide and to convert the source fatty acid to a polyunsaturated fatty acid selected from the group consisting of all-cis-7,10,13,16,19-docosapentaenoic acid (22:5, w-3) and docosatetraenoic acid,
- such that when all-cis-7,10,13,16,19-docosapentaenoic acid (22:5, w-3) is the source fatty acid, then docosahexaenoic acid is the polyunsaturated fatty acid produced;
- and
- when docosatetraenoic acid is the source fatty acid, then all-cis-4,7,10,13,16-docosapentaenoic acid (22:5, w-6) is the polyunsaturated fatty acid produced;
- and,
- c) optionally recovering the polyunsaturated fatty acid produced in step (b).
Dependencies are inferred from the claim text.