Table 1.

Description of fluxes and metabolites constituting the flux model of C. glutamicum

FluxConversion of metabolitesaEnzyme reaction(s)b
v1Glucose-6-P↔fructose-6-PGlucose-6-phosphate isomerase (EC 5.3.1.9 )
v2Fructose-6-P↔2 glyceraldehyde-3-P'sPhosphofructokinase (EC 2.7.1.11 ), fructose-1,6-bisphosphate aldolase (EC 4.1.2.13 ), triose phosphate isomerase (EC 5.3.1.1 )
v3Glyceraldehyde-3-P↔PEP/pyruvateGlyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12 ), 3-phosphoglycerate kinase (EC 2.7.2.3 ), phosphoglycerate mutase (EC 2.7.5.3 ), enolase (EC 4.2.1.11 )
v4Glucose-6-P↔pentose-5-P + CO2Glucose-6-phosphate dehydrogenase (EC 1.1.1.49 ), lactonase (EC 3.1.1.31 ), 6-phosphogluconate dehydrogenase (EC1.1.1.44 )
v52 Pentose-5-P's↔sedoheptulose-7-P + glyceraldehyde-3-PTransketolase (EC 2.2.1.1 )
v6Sedoheptulose-7-P + glyceraldehyde-3-P↔fructose-6-P + erythrose-4-PTransaldolase (EC 2.2.1.2 )
v7Erythrose-4-P + pentose-5-P↔fructose-6-P + glyceraldehyde-3-PTransketolase (EC2.2.1.1 )
v8PEP/pyruvate↔AcCoA + CO2Pyruvate dehydrogenase complex (EC 1.2.4.1 ; EC2.3.1.12 ; EC 1.8.1.4 )
v9AcCoA + malate/oxaloacetate↔isocitrateCitrate synthase (EC 4.1.3.7 ), aconitase (EC 4.2.1.3 )
v10Isocitrate↔oxoglutarate + CO2Isocitrate dehydrogenase (EC 1.1.1.42 )
v11Oxoglutarate↔succinate + CO22-Oxoglutarate dehydrogenase (EC 1.2.4.2 ; EC2.3.1.61 ; EC 1.8.1.4 ), succinyl CoA synthetase (EC 6.2.1.5 )
v12Succinate↔malate/oxaloacetateSuccinate dehydrogenase (EC 1.3.5.1 ), fumarase (EC 4.2.1.2 )
v13Isocitrate + AcCoA↔succinate + malate/oxaloacetateIsocitrate lyase (EC 4.1.3.1 ), malate synthase (EC 4.1.3.2 ), succinate dehydrogenase (EC 1.3.5.1 ), fumarase (EC4.2.1.2 )
v14PEP/pyruvate + CO2↔malate/oxaloacetatePEP carboxylase (EC 4.1.1.31 ), PEP carboxykinase (EC 4.1.1.32 ), pyruvate carboxylase (EC 6.4.1.1 ), oxaloacetate decarboxylase (EC 4.1.1.3 ), malic enzyme (EC1.1.1.40 )
  • a Pentose-5-phosphate combines ribose-5-phosphate, ribulose-5-phosphate, and xylulose-5-phosphate. P, phosphate; AcCoA, acetyl-CoA.

  • b Treating PEP and pyruvate, malate and oxaloacetate, and ribose-5-phosphate, ribulose-5-phosphate, and xylulose-5-phosphate as single pools precludes the assignment of fluxes for enzyme reactions interconverting these metabolites (pyruvate kinase [EC 2.7.1.40 ] and the PEP:glucose-phosphotransferase system [EC2.1.1.69 ; EC 2.7.3.9 ] for PEP/pyruvate, malate dehydrogenase [EC1.1.1.37 ] for malate/oxaloacetate, and ribose-5-phosphate isomerase [EC 5.3.1.6 ] and ribulose-5-phosphate epimerase [EC 5.1.3.1 ] for pentose-5-phosphates).