Pentose pathway, non-oxidative branch (WP379)

Saccharomyces cerevisiae

The reactions of the non-oxidative branch of the pentose phosphate pathway are reversible and are important for generating ribose-5-phosphate, which is required for the biosynthesis of several biomolecules, including RNA and DNA. The flow of glucose 6-phosphate through glycolysis and the pentose phosphate pathway is linked through two enzymes of the non-oxidative branch of the pentose phosphate pathway, transketolase (Tkl1p and Tkl2p) and transaldolase (Tal1p). The ability of these enzymes to convert one type of sugar into another allows them to convert the byproduct of one pathway into the substrate of another pathway in order to meet the metabolic needs of the cell. For example, if the cell needs ribose 5-phosphate, glyceraldehyde 3-phosphate and fructose 6-phosphate will be converted to ribose 5-phosphate. If the cell needs NADPH or ATP more than ribose 5-phosphate, ribose 5-phosphate will be converted to glyceraldehyde 3-phosphate and fructose 6-phosphate for use by the oxidative branch of the pentose phosphate pathway or glycolysis, respectively.


Meredith Braymer , Daniela Digles , Egon Willighagen , Denise Slenter , and Eric Weitz


last edited

Discuss this pathway

Check for ongoing discussions or start your own.

Cited In

Are you planning to include this pathway in your next publication? See How to Cite and add a link here to your paper once it's online.


Saccharomyces cerevisiae



Pathway Ontology

pentose phosphate pathway - non-oxidative phase


Label Type Compact URI Comment
NADP Metabolite chebi:44409
H+ Metabolite chebi:15378
H+ Metabolite chebi:15378
CO2 Metabolite chebi:16526
H2O Metabolite chebi:15377
6-phospho-gluconate Metabolite pubchem.compound:42609787
NADP Metabolite chebi:44409
D-6-Phospho-glucono-delta-lactone Metabolite chebi:16938 ID is for closed form, should be open...
fructose-6-phosphate Metabolite chemspider:26330295
NADPH Metabolite cas:53-57-6
glyceraldehyde-3-phosphate Metabolite cas:591-57-1
glucose-6-phosphate Metabolite cas:59-56-3
ribulose-5-phosphate Metabolite cas:4151-19-3
sedoheptulose-7-phosphate Metabolite cas:2646-35-7
xylulose-5-phosphate Metabolite chebi:27354
NADPH Metabolite cas:53-57-6
glyceraldehyde-3-phosphate Metabolite cas:591-57-1
D-ribose-5-phosphate Metabolite cas:3615-55-2
erythrose-4-phosphate Metabolite chebi:48153
RKI1 GeneProduct sgd:S000005621
GND1 GeneProduct sgd:S000001226
TKL2 GeneProduct sgd:S000000321
GND2 GeneProduct sgd:S000003488
TKL1 GeneProduct sgd:S000006278
ZWF1 GeneProduct sgd:S000005185
TAL1 GeneProduct sgd:S000004346
TKL1 GeneProduct sgd:S000006278
RPE1 GeneProduct sgd:S000003657


  1. Central carbon metabolism of Saccharomyces cerevisiae explored by biosynthetic fractional (13)C labeling of common amino acids. Maaheimo H, Fiaux J, Cakar ZP, Bailey JE, Sauer U, Szyperski T. Eur J Biochem. 2001 Apr;268(8):2464–79. PubMed Europe PMC Scholia
  2. Large-scale 13C-flux analysis reveals mechanistic principles of metabolic network robustness to null mutations in yeast. Blank LM, Kuepfer L, Sauer U. Genome Biol. 2005;6(6):R49. PubMed Europe PMC Scholia