MetaCyc Pathway: pyruvate fermentation to acetate and alanine
Inferred from experimentTraceable author statement to experimental support

Enzyme View:

Pathway diagram: pyruvate fermentation to acetate and alanine

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.

Synonyms: modified Embden-Meyerhof pathway, anaerobic glycolysis, fermentation, glycolysis 2, Embden-Meyerhof-Parnas pathway, EMP pathway, glycolysis II

Superclasses: Generation of Precursor Metabolites and EnergyFermentationPyruvate Fermentation

Some taxa known to possess this pathway include : Entamoeba histolytica, Pyrococcus furiosus

Expected Taxonomic Range: Amoebozoa, Archaea

Pyrococcus furiosus is a strict anaerobic archaeon, capable of utilizing pyruvate, sugars and complex organic compounds as carbon and energy sources. It is a facultative sulfur-reducing species that is able to grow in the absence of sulfur by fermentation of peptides, carbohydrates, and pyruvate. P. furiosus employs a modified glycolytic pathway for the catabolism of sugars, as shown in the pathway link. There are two ADP-dependent kinases, a glucokinase and a phosphofructokinase, and a tungsten-containing glyceraldehyde-3-phosphate ferredoxin oxidoreductase (GAPOR). GAPOR converts glyceraldehyde-3-phosphate into 3-phosphoglycerate in a single reaction. The main products of sugar fermentation are acetate, alanine, carbon dioxide, and hydrogen. [Adams01, deVos98, Kengen96, Ward00, Glasemacher97, Kengen95, Mai96, Mukund95]

Hydrogen is thought to be produced in the reactions involving GAPOR and pyruvate:ferredoxin oxidoreductase via coupled reactions with ferredoxin:NADP oxidoreductase and ferredoxin-dependent hydrogenase. However, the precise mechanism is not known. It has been postulated that the ferredoxin-dependent hydrogenase reaction generates oxidized ferredoxin for reuse by these enzymes. However, under conditions of high hydrogen pressure, hydrogenase activity is inhibited and alanine may be produced as a fermentation end product. Under these conditions, oxidation of reduced ferredoxin produced by GAPOR has been postulated to occur via ferredoxin:NADP oxidoreductase activity coupled with glutamate dehydrogenase and alanine aminotransferase reactions (in [Adams01] and reviewed in [Sakuraba02]).

A similar pathway leading from pyruvate to acetate has also been described in the human parasite Entamoeba histolytica [Reeves77].

Subpathways: L-alanine biosynthesis II, pyruvate fermentation to acetate III, acetate formation from acetyl-CoA II

Variants: pyruvate fermentation to acetate and lactate I, pyruvate fermentation to acetate and lactate II, pyruvate fermentation to acetate I, pyruvate fermentation to acetate II, pyruvate fermentation to acetate IV, pyruvate fermentation to acetate V, pyruvate fermentation to acetate VI, pyruvate fermentation to acetate VII, pyruvate fermentation to acetate VIII, pyruvate fermentation to acetone, pyruvate fermentation to butanoate, pyruvate fermentation to butanol I, pyruvate fermentation to butanol II, pyruvate fermentation to ethanol I, pyruvate fermentation to ethanol II, pyruvate fermentation to ethanol III, pyruvate fermentation to hexanol, pyruvate fermentation to isobutanol (engineered), pyruvate fermentation to lactate, pyruvate fermentation to opines, pyruvate fermentation to propanoate I, pyruvate fermentation to propanoate II (acrylate pathway), superpathway of Clostridium acetobutylicum acidogenic and solventogenic fermentation, superpathway of Clostridium acetobutylicum acidogenic fermentation, superpathway of Clostridium acetobutylicum solventogenic fermentation, superpathway of fermentation (Chlamydomonas reinhardtii)

Created 01-Feb-2006 by Fulcher CA, SRI International


Adams01: Adams MW, Holden JF, Menon AL, Schut GJ, Grunden AM, Hou C, Hutchins AM, Jenney FE, Kim C, Ma K, Pan G, Roy R, Sapra R, Story SV, Verhagen MF (2001). "Key role for sulfur in peptide metabolism and in regulation of three hydrogenases in the hyperthermophilic archaeon Pyrococcus furiosus." J Bacteriol 2001;183(2);716-24. PMID: 11133967

deVos98: de Vos WM, Kengen SW, Voorhorst WG, van der Oost J (1998). "Sugar utilization and its control in hyperthermophiles." Extremophiles 1998;2(3);201-5. PMID: 9783166

Glasemacher97: Glasemacher J, Bock AK, Schmid R, Schonheit P (1997). "Purification and properties of acetyl-CoA synthetase (ADP-forming), an archaeal enzyme of acetate formation and ATP synthesis, from the hyperthermophile Pyrococcus furiosus." Eur J Biochem 1997;244(2);561-7. PMID: 9119024

Kengen95: Kengen SW, Tuininga JE, de Bok FA, Stams AJ, de Vos WM (1995). "Purification and characterization of a novel ADP-dependent glucokinase from the hyperthermophilic archaeon Pyrococcus furiosus." J Biol Chem 1995;270(51);30453-7. PMID: 8530474

Kengen96: Kengen, S.M., Stams, A.J.M., de Vos, W.M. (1996). "Sugar metabolism of hyperthermophiles." FEMS Microbiol. Re. 18(2-3): 119-137.

Mai96: Mai X, Adams MW (1996). "Purification and characterization of two reversible and ADP-dependent acetyl coenzyme A synthetases from the hyperthermophilic archaeon Pyrococcus furiosus." J Bacteriol 1996;178(20);5897-903. PMID: 8830684

Mukund95: Mukund S, Adams MW (1995). "Glyceraldehyde-3-phosphate ferredoxin oxidoreductase, a novel tungsten-containing enzyme with a potential glycolytic role in the hyperthermophilic archaeon Pyrococcus furiosus." J Biol Chem 1995;270(15);8389-92. PMID: 7721730

Reeves77: Reeves RE, Warren LG, Susskind B, Lo HS (1977). "An energy-conserving pyruvate-to-acetate pathway in Entamoeba histolytica. Pyruvate synthase and a new acetate thiokinase." J Biol Chem 252(2);726-31. PMID: 13076

Sakuraba02: Sakuraba H, Ohshima T (2002). "Novel energy metabolism in anaerobic hyperthermophilic archaea: a modified Embden-Meyerhof pathway." J Biosci Bioeng 93(5);441-8. PMID: 16233230

Ward00: Ward DE, Kengen SW, van Der Oost J, de Vos WM (2000). "Purification and characterization of the alanine aminotransferase from the hyperthermophilic Archaeon pyrococcus furiosus and its role in alanine production." J Bacteriol 2000;182(9);2559-66. PMID: 10762259

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

Barrett78: Barrett J, Coles GC, Simpkin KG (1978). "Pathways of acetate and propionate production in adult Fasciola hepatica." Int J Parasitol 8(2);117-23. PMID: 681067

Beh93: Beh M, Strauss G, Huber R, Stetter K-O, Fuchs G (1993). "Enzymes of the reductive citric acid cycle in the autotrophic eubacterium Aquifex pyrophilus and in the archaebacterium Thermoproteus neutrophilus." Arch Microbiol 160: 306-311.

Blamey93: Blamey JM, Adams MW (1993). "Purification and characterization of pyruvate ferredoxin oxidoreductase from the hyperthermophilic archaeon Pyrococcus furiosus." Biochim Biophys Acta 1161(1);19-27. PMID: 8380721

Blamey94: Blamey JM, Adams MW (1994). "Characterization of an ancestral type of pyruvate ferredoxin oxidoreductase from the hyperthermophilic bacterium, Thermotoga maritima." Biochemistry 1994;33(4);1000-7. PMID: 8305426

Blaschkowski82: Blaschkowski HP, Neuer G, Ludwig-Festl M, Knappe J (1982). "Routes of flavodoxin and ferredoxin reduction in Escherichia coli. CoA-acylating pyruvate: flavodoxin and NADPH: flavodoxin oxidoreductases participating in the activation of pyruvate formate-lyase." Eur J Biochem 123(3);563-9. PMID: 7042345

Brasen01: Brasen C, Schonheit P (2001). "Mechanisms of acetate formation and acetate activation in halophilic archaea." Arch Microbiol 175(5);360-8. PMID: 11409546

Brasen04: Brasen C, Schonheit P (2004). "Regulation of acetate and acetyl-CoA converting enzymes during growth on acetate and/or glucose in the halophilic archaeon Haloarcula marismortui." FEMS Microbiol Lett 241(1);21-6. PMID: 15556705

Brown77: Brown TD, Jones-Mortimer MC, Kornberg HL (1977). "The enzymic interconversion of acetate and acetyl-coenzyme A in Escherichia coli." J Gen Microbiol 1977;102(2);327-36. PMID: 21941

Catalanotti12: Catalanotti C, Dubini A, Subramanian V, Yang W, Magneschi L, Mus F, Seibert M, Posewitz MC, Grossman AR (2012). "Altered fermentative metabolism in Chlamydomonas reinhardtii mutants lacking pyruvate formate lyase and both pyruvate formate lyase and alcohol dehydrogenase." Plant Cell 24(2);692-707. PMID: 22353371

Felbeck80: Felbeck H, Grieshaber MK (1980). "Investigations on some enzymes involved in the anaerobic metabolism of amino acids of Arenicola marina L." Comparative Biochemistry and Physiology Part B: Comparative Biochemistry 66(2);205-213.

Hemschemeier08: Hemschemeier A, Jacobs J, Happe T (2008). "Biochemical and physiological characterization of the pyruvate formate-lyase Pfl1 of Chlamydomonas reinhardtii, a typically bacterial enzyme in a eukaryotic alga." Eukaryot Cell 7(3);518-26. PMID: 18245276

Hutchins01: Hutchins AM, Mai X, Adams MW (2001). "Acetyl-CoA synthetases I and II from Pyrococcus furiosus." Methods Enzymol 331;158-67. PMID: 11265458

Ikeda06: Ikeda T, Ochiai T, Morita S, Nishiyama A, Yamada E, Arai H, Ishii M, Igarashi Y (2006). "Anabolic five subunit-type pyruvate:ferredoxin oxidoreductase from Hydrogenobacter thermophilus TK-6." Biochem Biophys Res Commun 340(1);76-82. PMID: 16343420

Ishiguro91: Ishiguro M, Takio K, Suzuki M, Oyama R, Matsuzawa T, Titani K (1991). "Complete amino acid sequence of human liver cytosolic alanine aminotransferase (GPT) determined by a combination of conventional and mass spectral methods." Biochemistry 30(43);10451-7. PMID: 1931970

Kao93: Kao MC, Chung MC (1993). "Pyridylethylation of cysteine residues in proteins." Anal Biochem 1993;215(1);82-5. PMID: 8297018

Kerscher77: Kerscher L, Oesterhelt D (1977). "Ferredoxin is the coenzyme of alpha-ketoacid oxidoreductases in Halobacterium halobium." FEBS Lett 1977;83(2);197-201. PMID: 201489

Kerscher81: Kerscher L, Oesterhelt D (1981). "Purification and properties of two 2-oxoacid:ferredoxin oxidoreductases from Halobacterium halobium." Eur J Biochem 1981;116(3);587-94. PMID: 6266826

Kerscher81a: Kerscher L, Oesterhelt D (1981). "The catalytic mechanism of 2-oxoacid:ferredoxin oxidoreductases from Halobacterium halobium. One-electron transfer at two distinct steps of the catalytic cycle." Eur J Biochem 1981;116(3);595-600. PMID: 6266827

Kim10: Kim SH, Schneider BL, Reitzer L (2010). "Genetics and regulation of the major enzymes of alanine synthesis in Escherichia coli." J Bacteriol 192(20);5304-11. PMID: 20729367

Kletzin96: Kletzin A, Adams MW (1996). "Molecular and phylogenetic characterization of pyruvate and 2-ketoisovalerate ferredoxin oxidoreductases from Pyrococcus furiosus and pyruvate ferredoxin oxidoreductase from Thermotoga maritima." J Bacteriol 1996;178(1);248-57. PMID: 8550425

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
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