Synthetic biochemistry molecular purge valve module that maintain co-factor balance
The disclosure provides a metabolic pathway for producing a metabolite, the metabolic pathway having a co-factor purge valve system for recycling a cofactor used in the metabolic pathway.
1. A recombinant, artificial or engineered metabolic pathway comprising a plurality of enzymatic steps that converts a substrate to a product, wherein the pathway produces an unbalanced production of a cofactor, said pathway comprising:
a first cofactor-dependent enzyme that is capable of converting a first substrate to a second substrate, said enzyme producing the unbalanced production of a cofactor; and
a second cofactor-dependent enzyme comprising an NADH or an NADPH oxidase that recycles the cofactor.
2. The recombinant, artificial or engineered pathway of claim 1 , wherein the co-factor is an oxidizing/reducing co-factor.
3. The recombinant, artificial or engineered pathway of claim 2 , wherein the oxidizing/reducing co-factor is selected from the group consisting of NAD + /NADH, NADP + /NADPH and FAD + /FADH.
4. The recombinant, artificial or engineered pathway of claim 1 , wherein the cofactor comprises NAD + /NADH or NADP + /NADPH.
5. The recombinant, artificial or engineered pathway of claim 1 , wherein the first cofactor-dependent enzyme comprises an NADH or an NADPH dehydrogenase.
6. The recombinant, artificial or engineered pathway of claim 5 , wherein the NADH dehydrogenase is a NADH pyruvate dehydrogenase complex.
7. The recombinant, artificial or engineered pathway of claim 6 , wherein the NADH pyruvate dehydrogenase complex comprises a pyruvate dehydrogenase subunit a, a pyruvate dehydrogenase subunit b, a dihydrolipoamide acetyltransferase, and a dihydrolipoamide dehydrogenase.
8. The recombinant, artificial or engineered pathway of claim 7 , wherein the pyruvate dehydrogenase subunit a comprises a sequence that has at least 90% sequence identity to SEQ ID NO: 1, wherein the pyruvate dehydrogenase subunit b comprises a sequence that has at least 90% sequence identity to SEQ ID NO: 2, wherein the dihydrolipoamide acetyltransferase has at least 90% sequence identity to SEQ ID NO: 3, and wherein the dihydrolipoamide dehydrogenase has at least 90% sequence identity to SEQ ID NO: 5, wherein the complex converts pyruvate to acetyl-CoA.
9. The recombinant, artificial or engineered pathway of claim 7 , wherein the pyruvate dehydrogenase subunit a comprises a sequence that has at least 90% sequence identity to SEQ ID NO: 1, wherein the pyruvate dehydrogenase subunit b comprises a sequence that has at least 90% sequence identity to SEQ ID NO: 2, wherein the dihydrolipoamide acetyltransferase has at least 90% sequence identity to SEQ ID NO: 3, and wherein the dihydrolipoamide dehydrogenase has at least 90% sequence identity to SEQ ID NO: 7 and preferentially uses NADP + , wherein the complex converts pyruvate to acetyl-CoA.
10. The recombinant, artificial or engineered pathway of claim 5 , wherein the NADPH dehydrogenase is a member of a NADPH pyruvate dehydrogenase complex.
11. The recombinant, artificial or engineered pathway of claim 10 , wherein the NADPH pyruvate dehydrogenase complex comprises a pyruvate dehydrogenase subunit a, a pyruvate dehydrogenase subunit b, a dihydrolipoamide acetyltransferase, and a mutant dihydrolipoamide dehydrogenase the preferentially uses NADP + .
12. The recombinant, artificial or engineered pathway of claim 1 , wherein the NADH or the NADPH oxidase is a NoxE or homolog thereof.
13. The recombinant, artificial or engineered pathway of claim 12 , wherein the NADH or the NADPH oxidase comprises a sequence that has at least 50% sequence identity to SEQ ID NO: 10.
14. The recombinant, artificial or engineered pathway of claim 1 , wherein the pathway is in a cell-free system.
15. The recombinant, artificial or engineered pathway of claim 1 , wherein the pathway is in a living cell.
16. The recombinant, artificial or engineered pathway of claim 1 , wherein the recombinant, artificial or engineered pathway produces PHB.
17. The recombinant, artificial or engineered pathway of claim 1 , wherein the recombinant, artificial or engineered pathway produces ethanol.
18. The recombinant, artificial or engineered pathway of claim 1 , wherein the recombinant, artificial or engineered pathway produces lactate.
19. An enzymatic system comprising a metabolic pathway including a plurality of enzymes for converting a substrate to a product, the metabolic pathway having an unbalanced utilization of reducing/oxidizing cofactors, wherein the enzymatic system comprises a metabolic purge valve comprising an NADH pyruvate dehydrogenase and a NADH/NADPH oxidase.
20. A recombinant polypeptide comprising a sequence that has at least 99% sequence identity to SEQ ID NO: 5 and comprising the mutations E206V, G207R, A208K, and S213R, wherein the polypeptide has dihydrolipoamide dehydrogenase activity.