Glucose valve and other metabolite valves
Aspects of the invention relate to the design and construction of Metabolite Valves, such as Glucose Valves, that can be used to divert metabolites from endogenous pathways toward alternative pathways in a cell.
1. A method for redirecting glycolytic flux in a E. coli cell, the method comprising reducing expression of the phosphoenolpyruvate (PEP)-dependent glucose phosphotransferase system (PTS) in the cell and inhibiting phosphorylation of glucose by glucokinase within the cell, wherein the cell has increased expression of galactose permease (ga/P) and/or glucose facilitator protein (glf), wherein inhibiting phosphorylation of glucose by glucokinase within the cell comprises reducing expression of glucokinase in the cell, wherein reducing expression of glucokinase in the cell comprises recombinantly expressing in the cell an antisense RNA transcript that targets glucokinase, or replacing the promoter of glukokinase with a repressible promoter.
2. The method of claim 1 , wherein expression of glucose-6-phosphate isomerase in the cell is reduced.
3. The method of claim 2 , wherein reduced expression of glucose-6-phosphate isomerase in the cell comprises recombinantly expressing in the cell an antisense RNA transcript that targets glucose-6-phosphate isomerase.
4. The method of claim 1 , wherein the cell recombinantly expresses an inducible repressor protein that represses glucokinase expression.
5. The method of claim 1 , wherein the cell is a microbial cell.
6. The method of claim 1 , wherein the method is a method of producing gluconate and the method further comprises culturing the cell and optionally recovering gluconate from the cell and/or cell culture, or wherein the method is a method of producing glucaric acid and the method further comprises culturing the cell and optionally recovering glucaric acid from the cell and/or cell culture.
7. The method of claim 1 , wherein the cell recombinantly expresses a gene encoding for glucose dehydrogenase (gdh).
8. The method of claim 1 , wherein the cell recombinantly expresses a gene encoding for galactose permease (galP) and/or glucose facilitator protein (glf).