Chimeric PUFA polyketide synthase systems and uses thereof
View Patent ↗Disclosed are chimeric polyunsaturated fatty acid (PUFA) polyketide synthase (PKS) proteins and chimeric PUFA PKS systems, including chimeric PUFA PKS proteins and systems derived from Schizochytrium and Thraustochytrium . Disclosed are nucleic acids and proteins encoding such chimeric PUFA PKS proteins and systems, genetically modified organisms comprising such chimeric PUFA PKS proteins and systems, and methods of making and using such chimeric PUFA PKS proteins and systems.
1. A genetically modified microorganism or plant or part of the plant, comprising a chimeric polyunsaturated fatty acid (PUFA) polyketide synthase (PKS) system, wherein the chimeric PUFA PKS system comprises a replacement of a FabA-like β-hydroxyacyl-ACP dehydrase-2 (DH2) domain in a Schizochytrium PUFA PKS system with a DH2 domain from a Thraustochytrium PUFA PKS system, and wherein the chimeric PUFA PKS system produces a ratio of omega-3 to omega-6 PUFAs that is different from the ratio of omega-3 to omega-6 PUFAs produced by the Schizochytrium PUFA PKS system.
2. The genetically modified microorganism or plant or part of the plant of claim 1 , wherein the chimeric PUFA PKS system comprises a replacement of OrfC in the Schizochytrium PUFA PKS system with OrfC from the Thraustochytrium PUFA PKS system.
3. The genetically modified microorganism or plant or part of the plant of claim 2 , wherein the chimeric PUFA PKS system further comprises a replacement of OrfA in the Schizochytrium PUFA PKS system with OrfA from a Thraustochytrium PUFA PKS system.
4. The genetically modified microorganism or plant or part of the plant of claim 2 , wherein the chimeric PUFA PKS system further comprises a replacement of OrfB in the Schizochytrium PUFA PKS system with OrfB from a Thraustochytrium PUFA PKS system.
5. The genetically modified microorganism or plant or part of the plant of claim 1 , wherein the DH2 domain from the Thraustochytrium PUFA PKS system is from Thraustochytrium 23B.
6. The genetically modified microorganism or plant or part of the plant of claim 5 , wherein the nucleic acid sequence encoding the DH2 domain from Thraustochytrium 23B comprises SEQ ID NO:73.
7. The genetically modified microorganism or plant or part of the plant of claim 5 , wherein the nucleic acid sequence encoding the DH2 domain from Thraustochytrium 23B comprises SEQ ID NO:75.
8. The genetically modified microorganism or plant or part of the plant of claim 1 , wherein the DH2 domain from the Thraustochytrium PUFA PKS system is encoded by a nucleic acid sequence optimized for Schizochytrium codon usage.
9. A genetically modified microorganism or plant or part of the plant comprising a chimeric PUFA PKS system, wherein the chimeric PUFA PKS system comprises a replacement of OrfC in a Schizochytrium PUFA PKS system with OrfC from a Thraustochytrium PUFA PKS system that is encoded by a nucleic acid sequence optimized for Schizochytrium codon usage, and wherein the chimeric PUFA PKS system produces a ratio of omega-3 to omega-6 PUFAs that is different from the ratio of omega-3 to omega-6 PUFAs produced by the Schizochytrium PUFA PKS system.
10. The genetically modified microorganism or plant or part of the plant of claim 9 , wherein the nucleic acid sequence encoding the OrfC from the Thraustochytrium PUFA PKS system comprises SEQ ID NO:70.
11. The genetically modified microorganism or plant or part of the plant of claim 9 , wherein the chimeric PUFA PKS system further comprises a replacement of OrfA in the Schizochytrium PUFA PKS system with OrfA from a Thraustochytrium PUFA PKS system, wherein the OrfA from the Thraustochytrium PUFA PKS system is encoded by a nucleic acid sequence optimized for Schizochytrium codon usage.
12. The genetically modified microorganism or plant or part of the plant of claim 11 , wherein the nucleic acid sequence encoding the OrfA from the Thraustochytrium PUFA PKS system comprises SEQ ID NO:71.
13. The genetically modified microorganism or plant or part of the plant of claim 9 , wherein the chimeric PUFA PKS system further comprises a replacement of OrfB in the Schizochytrium PUPA PKS system with OrfB from a Thraustochytrium PUFA PKS system, wherein the OrfB from the Thraustochytrium PUFA PKS system is encoded by a nucleic acid sequence optimized for Schizochytrium codon usage.
14. The genetically modified microorganism or plant or part of the plant of claim 13 , wherein the nucleic acid sequence encoding the OrfB from the Thraustochytrium PUFA PKS system comprises SEQ ID NO:72.
15. A genetically modified microorganism or plant or part of the plant, comprising a chimeric polyunsaturated fatty acid (PUFA) polyketide synthase (PKS) system, wherein the chimeric PUFA PKS system comprises a replacement of a FabA-like β-hydroxyacyl-ACP dehydrase-2 (DH2) domain in a first PUPA PKS system with a DH2 domain from a second PUFA PKS system having a different amino acid sequence from the DH2 domain of the first PUFA PKS system, wherein the DH2 domain from the second PUFA PKS system is at least 95% identical to SEQ ID NO:74, wherein the chimeric PUFA PKS system produces a ratio of omega-3 to omega-6 PUFAs that is different from the ratio of omega-3 to omega-6 PUFAs produced by the first PUFA PKS system.
16. The genetically modified microorganism or plant or part of the plant of claim 15 , wherein the chimeric PUFA PKS system comprises SEQ ID NO:2, SEQ ID NO:4, and SEQ ID NO:74.
17. The genetically modified microorganism or plant or part of the plant of claim 15 , wherein the chimeric PUFA PKS system is encoded by nucleic acid molecules comprising: SEQ ID NO:1, SEQ ID NO:3, and SEQ ID NO:75.
18. The genetically modified microorganism or plant or part of the plant of claim 1 , wherein said microorganism or plant or part of the plant has been transfected with at least one nucleic acid molecule encoding a 4′-phosphopantetheinyl transferase (PPTase).
19. The genetically modified microorganism or plant or part of the plant of claim 2 , wherein the OrfC from the Thraustochytrium PUFA PKS system is the OrfC from Thraustochytrium 23B.
20. The genetically modified microorganism or plant or part of the plant of claim 3 , wherein the OrfA from the Thraustochytrium PUFA PKS system is the OrfA from Thraustochytrium 23B.
21. The genetically modified microorganism or plant or part of the plant of claim 4 , wherein the OrfB from the Thraustochytrium PUFA PKS system is the OrfB from Thraustochytrium 23B.
22. The genetically modified microorganism or plant or part of the plant of claim 9 , wherein said microorganism or plant or part of the plant has been transfected with at least one nucleic acid molecule encoding a 4′-phosphopantetheinyl transferase (PPTase).
23. The genetically modified microorganism or plant or part of the plant of claim 9 , wherein the OrfC from the Thraustochytrium PUPA PKS system is the OrfC from Thraustochytrium 23B.
24. The genetically modified microorganism or plant or part of the plant of claim 11 , wherein the OrfA from the Thraustochytrium PUFA PKS system is the OrfA from Thraustochytrium 23B.
25. The genetically modified microorganism or plant or part of the plant of claim 13 , wherein the OrfB from the Thraustochytrium PUFA PKS system is the OrfB from Thraustochytrium 23B.
26. The genetically modified microorganism or plant or part of the plant of claim 14 , wherein said microorganism or plant or part of the plant has been transfected with at least one nucleic acid molecule encoding a 4′-phosphopantetheinyl transferase (PPTase).