Nucleic acid which is obtained fromTetrahymenaand which codes for a delta-6-desaturase, the production thereof and use

• US 7,135,623 B1
• Filed: 09/08/2000
• Issued: 11/14/2006
• Est. Priority Date: 09/10/1999
• Status: Expired due to Fees

• Current Assignee: Nutrinova Nutrition Specialties & Food Ingredients GmbH (Celanese Corporation)
• Original Assignee: Nutrinova Nutrition Specialties & Food Ingredients GmbH (Celanese Corporation)
• Inventors: Rusing, Matthias, Dominitzki, Annette, Kiy, Thomas
• Primary Examiner(s): McElwain, Elizabeth F.
• Application Number:
  US10/070,666
• Time in Patent Office: 2,258 Days
• Field of Search: 536/23.2, 435/4, 435/320.1, 800/13, 800/298
• US Class Current: 800/298
• CPC Class Codes: C12N 9/0083 Miscellaneous (1.14.99)
• CPC Class Codes: C12P 7/6427 Polyunsaturated fatty acids [PUFA], i.e. having two or more double bonds in their backbone
• CPC Class Codes: C12P 7/6472 containing polyunsaturated fatty acid [PUFA] residues, i.e. having two or more double bonds in their backbone

Abstract

The invention relates to nucleic acid(s) which is/are obtained from tetrahymena and which code(s) for a ciliate-specific delta-6-desaturase that is involved in the biosynthesis of commercially valuable, multiply unsaturated fatty acids (so-called PUFA) polyunsaturated fatty acids). The inventive nucleotide sequence and the polypeptide sequence that can be obtained therefrom exhibit a surprisingly low sequence identity compared to other known natural desaturases. The invention also relates to the use of the nucleic acid(s) for overexpression in ciliates, preferably tetrahymena, in particular, Tetrahymena thermophila, with the aim of increasing the production of delta-6 unsaturated fatty acids, especially GLA.

Claims

1. An isolated nucleic acid encoding Tetrahymena delta-6-desaturase as shown in SEQ ID NO:

2.

2. An isolated nucleic acid as claimed in claim 1, which is obtained from Tetrahymena thermophila.

3. An isolated nucleic acid as claimed in claim 1 which is DNA.

4. An isolated nucleic acid as claimed in claim 1, which is a DNA comprising a nucleic acid sequence as depicted in SEQ ID. NO.:

1 from position 33 to position 1091.

5. An isolated nucleic acid as claimed in claim 1 comprising one or more noncoding sequences.

11. The isolated nucleic acid of claim 3 in which the DNA is double-stranded DNA.

22. An isolated nucleic acid as claimed in claim 1 which is RNA.

23. An isolated nucleic acid as claimed in claim 1, which is obtained from a ciliate.

6. A vector comprising a nucleic acid encoding Tetrahymena delta-6-desaturase as shown in SEQ ID NO:

2.

7. The vector of claim 6, wherein the nucleic acid is functionally combined with a constitutive promoter.

12. The vector of claim 6 in which the vector is an expression vector.

13. The vector of claim 6 wherein the nucleic acid is functionally combined with an inducible promoter.

14. The vector of claim 7 wherein the nucleic acid is functionally combined with an inducible promoter.

15. The vector of claim 7 wherein the nucleic acid further comprises a termination signal.

16. The vector of claim 13 wherein the nucleic acid further comprises a termination signal.

17. The vector of claim 14 wherein the nucleic acid further comprises a termination signal.

19. The process of claim 12 in which the expression vector is in a host organism.

8. A process for preparing a nucleic acid encoding Tetrahymena delta-6-desaturase as shown in SEQ ID NO:

2, the process comprising chemically synthesizing the nucleic acid.

9. A transgenic, nonhuman organism comprising a nucleic acid encoding Tetrahymena delta-6-desaturase as shown in SEQ ID NO:

2.

10. The transgenic organism of claim 9 in which the transgenic organism is a plant or a ciliate.

18. A process for preparing a nucleic acid encoding Tetrahymena delta-6-desaturase as shown in SEQ ID NO:

2, the process comprising isolating the nucleic acid from a gene library using a probe which hybridizes to the nucleic acid.

20. A method of enriching delta-6-desaturase dependent fatty acids in ciliates, the method comprising:

inserting a vector comprising a nucleic acid encoding Tetrahymena delta-6-desaturase as shown in SEQ ID NO;

2 into a ciliate; and

expressing the nucleic acid to enrich delta-6-desaturase dependent fatty acids in the ciliate.

21. The method of claim 20 in which the vector comprises at least one inducible promoter.