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MetaCyc Pathway: pentose phosphate pathway (non-oxidative branch)
Inferred from experiment

Pathway diagram: pentose phosphate pathway (non-oxidative branch)

This view shows enzymes only for those organisms listed below, in the list of taxa known to possess the pathway. If an enzyme name is shown in bold, there is experimental evidence for this enzymatic activity.

Superclasses: Generation of Precursor Metabolites and EnergyPentose Phosphate Pathways

Some taxa known to possess this pathway include : Escherichia coli K-12 substr. MG1655Inferred from experiment

Expected Taxonomic Range: Bacteria , Eukaryota

General Background

The pentose phosphate pathway is an alternative way of oxidizing glucose, and in this pathway the oxidation is coupled to NADPH synthesis. As a result, the pentose phosphate pathway is a major source of reducing equivalents for biosynthesis reactions. The pentose phosphate pathway is also important for the conversion of hexoses to pentoses [Zubay83] .

About This Pathway

The pentose phosphate pathway is one of the three essential pathways of central metabolism. It supplies three of Escherichia coli's 13 precursor metabolites (compounds needed for the biosyntheses): D-ribose 5-phosphate, D-sedoheptulose 7-phosphate, and D-erythrose 4-phosphate. Regardless of the carbon source upon which Escherichia coli is growing, some carbon must flow through the pentose phosphate pathway to meet the cell's requirements for these metabolites. In addition this pathway is an important source of NADPH, which is also needed for biosyntheses. The pathway begins with one intermediate of glycolysis, β-D-glucose 6-phosphate, and ends with the formation of two others, β-D-fructofuranose 6-phosphate and D-glyceraldehyde 3-phosphate.

For convenience, the pentose phosphate pathway is commonly divided into its preliminary oxidative portion, in which β-D-glucose 6-phosphate is oxidized to D-ribulose 5-phosphate, and its subsequent non-oxidative portion in which through a series of transaldolase and transketolase reactions, D-ribulose 5-phosphate is converted into β-D-fructofuranose 6-phosphate and D-glyceraldehyde 3-phosphate.

Citations: [Wood86]

Superpathways: pentose phosphate pathway, superpathway of glucose and xylose degradation

Variants: pentose phosphate pathway (oxidative branch), pentose phosphate pathway (partial)

Unification Links: EcoCyc:NONOXIPENT-PWY

Created 04-Apr-1994 by Riley M, Marine Biological Laboratory
Revised 13-Jul-2006 by Ingraham JL, UC Davis


Wood86: Wood T (1986). "Distribution of the pentose phosphate pathway in living organisms." Cell Biochem Funct 4(4);235-40. PMID: 3539385

Zubay83: Zubay, G "Biochemistry." Addison-Wesley Publishing Company, Inc., 1983.

Other References Related to Enzymes, Genes, Subpathways, and Substrates of this Pathway

Asztalos07: Asztalos P, Parthier C, Golbik R, Kleinschmidt M, Hubner G, Weiss MS, Friedemann R, Wille G, Tittmann K (2007). "Strain and near attack conformers in enzymic thiamin catalysis: X-ray crystallographic snapshots of bacterial transketolase in covalent complex with donor ketoses xylulose 5-phosphate and fructose 6-phosphate, and in noncovalent complex with acceptor aldose ribose 5-phosphate." Biochemistry 46(43);12037-52. PMID: 17914867

Aucamp08: Aucamp JP, Martinez-Torres RJ, Hibbert EG, Dalby PA (2008). "A microplate-based evaluation of complex denaturation pathways: structural stability of Escherichia coli transketolase." Biotechnol Bioeng 99(6);1303-10. PMID: 17969139

Bairoch93a: Bairoch A, Boeckmann B (1993). "The SWISS-PROT protein sequence data bank, recent developments." Nucleic Acids Res. 21:3093-3096. PMID: 8332529

Benov99: Benov L, Fridovich I (1999). "Why superoxide imposes an aromatic amino acid auxotrophy on Escherichia coli. The transketolase connection." J Biol Chem 274(7);4202-6. PMID: 9933617

Binkowski05: Binkowski TA, Joachimiak A, Liang J (2005). "Protein surface analysis for function annotation in high-throughput structural genomics pipeline." Protein Sci 14(12);2972-81. PMID: 16322579

BRENDA14: BRENDA team (2014). Imported from BRENDA version existing on Aug 2014.

Butland05: Butland G, Peregrin-Alvarez JM, Li J, Yang W, Yang X, Canadien V, Starostine A, Richards D, Beattie B, Krogan N, Davey M, Parkinson J, Greenblatt J, Emili A (2005). "Interaction network containing conserved and essential protein complexes in Escherichia coli." Nature 433(7025);531-7. PMID: 15690043

Chandran03: Chandran SS, Yi J, Draths KM, von Daeniken R, Weber W, Frost JW (2003). "Phosphoenolpyruvate availability and the biosynthesis of shikimic acid." Biotechnol Prog 19(3);808-14. PMID: 12790643

Chauhan96: Chauhan RP, Woodley JM, Powell LW (1996). "In situ product removal from E. coli transketolase-catalyzed biotransformations." Ann N Y Acad Sci 799;545-54. PMID: 8958111

Dalby07: Dalby PA, Aucamp JP, George R, Martinez-Torres RJ (2007). "Structural stability of an enzyme biocatalyst." Biochem Soc Trans 35(Pt 6);1606-9. PMID: 18031275

David70: David J, Wiesmeyer H (1970). "Regulation of ribose metabolism in Escherichia coli. II. Evidence for two ribose-5-phosphate isomerase activities." Biochim Biophys Acta 208(1);56-67. PMID: 4909663

DeSantis89: DeSantis D, Tryon VV, Pollack JD "Metabolism of Mollicutes: the Embden-Meyerhof-Parnas Pathway and the Hexose Monophosphate Shunt." J General Microbiology 135:683-691 (1989).

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

Domain07: Domain F, Bina XR, Levy SB (2007). "Transketolase A, an enzyme in central metabolism, derepresses the marRAB multiple antibiotic resistance operon of Escherichia coli by interaction with MarR." Mol Microbiol 66(2);383-94. PMID: 17850260

Edwards00: Edwards JS, Palsson BO (2000). "Robustness analysis of the Escherichia coli metabolic network." Biotechnol Prog 16(6);927-39. PMID: 11101318

Essenberg75: Essenberg MK, Cooper RA (1975). "Two ribose-5-phosphate isomerases from Escherichia coli K12: partial characterisation of the enzymes and consideration of their possible physiological roles." Eur J Biochem 55(2);323-32. PMID: 1104357

Flores96: Flores N, Xiao J, Berry A, Bolivar F, Valle F (1996). "Pathway engineering for the production of aromatic compounds in Escherichia coli." Nat Biotechnol 14(5);620-3. PMID: 9630954

Follstad98: Follstad BD, Stephanopoulos G (1998). "Effect of reversible reactions on isotope label redistribution--analysis of the pentose phosphate pathway." Eur J Biochem 252(3);360-71. PMID: 9546650

French96: French C, Ward JM (1996). "Production and modification of E. coli transketolase for large-scale biocatalysis." Ann N Y Acad Sci 799;11-8. PMID: 8958067

Gaudet10: Gaudet P, Livstone M, Thomas P (2010). "Annotation inferences using phylogenetic trees." PMID: 19578431

Showing only 20 references. To show more, press the button "Show all references".

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by Pathway Tools version 19.5 (software by SRI International) on Sun May 1, 2016, biocyc14.