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MetaCyc Pathway: oxalate degradation IV
Inferred from experiment

Enzyme View:

Pathway diagram: oxalate degradation IV

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: Degradation/Utilization/AssimilationCarboxylates DegradationOxalate Degradation

Some taxa known to possess this pathway include : Gelatoporia subvermispora, Hordeum vulgare, Triticum aestivum

Expected Taxonomic Range: Bacteria , Fungi, Viridiplantae

Oxalate is the most oxidized two-carbon compound. It is made in high concentrations by some plants and fungi and can reach high micromolar concentrations in soil. Oxalate is toxic to mammals but is metabolized by many bacteria and plants by various pathways.

Oxalate oxidase, an enzyme that catalyzes the oxidative cleavage of oxalate to carbon dioxide with reduction of dioxygen to hydrogen peroxide, is widespread in cereal plants [Lane02, Lane00, Lane93]. The enzyme has also been described in bacteria [Koyama88] and fungi [Escutia05], although it does not appear to be common in these organisms.

Germin is a hydrogen peroxide generating enzyme found in several plant species, including barley ( Hordeum vulgare) and wheat ( Triticum aestivum), and some fungi. Germin's synthesis coincides with the onset of growth in germinating wheat embryos (hence the name). The enzyme serves as a marker of embryonic development in germinating wheat grains

The enzyme has been shown to be an oxalate oxidase [Dumas93, Lane93] that is involved in the defense against biotic and abiotic stress in plants [Lane02]. Enzyme activity is detected in barley seedling roots during development and in the leaves of mature plants in response to powdery-mildew infection [Dumas95].

The exact nature of the elevated resistance to pathogens is still not clear, but several hypotheses exist [Lane02]:

(1) generation of microcidal concentrations of hydrogen peroxide

(2) elicitation of hypersensitive cell death at lower concentrations of hydrogen peroxide

(3) formation of effective barriers against predator penetration by the hydrogen-peroxide-mediated lignification of cell walls

(4) destruction of oxalate, which is an inhibitor of the hypersensitive response, a strategy employed byubiquitous predator organisms such as Sclerotinia sclerotiorum, which secretes high concentrations of oxalate as a toxin.

Variants: oxalate degradation I, oxalate degradation II, oxalate degradation III, oxalate degradation V

Created 20-Jan-2011 by Caspi R, SRI International


Dumas93: Dumas B, Sailland A, Cheviet JP, Freyssinet G, Pallett K (1993). "Identification of barley oxalate oxidase as a germin-like protein." C R Acad Sci III 316(8);793-8. PMID: 8044704

Dumas95: Dumas B, Freyssinet G, Pallett KE (1995). "Tissue-Specific Expression of Germin-Like Oxalate Oxidase during Development and Fungal Infection of Barley Seedlings." Plant Physiol 107(4);1091-1096. PMID: 12228419

Escutia05: Escutia MR, Bowater L, Edwards A, Bottrill AR, Burrell MR, Polanco R, Vicuna R, Bornemann S (2005). "Cloning and sequencing of two Ceriporiopsis subvermispora bicupin oxalate oxidase allelic isoforms: implications for the reaction specificity of oxalate oxidases and decarboxylases." Appl Environ Microbiol 71(7);3608-16. PMID: 16000768

Koyama88: Koyama, H. (1988). "Purification and characterization of oxalate oxidase from Pseudomonas sp. OX-53." Agric. Biol. Chem. 52:743-748.

Lane00: Lane BG (2000). "Oxalate oxidases and differentiating surface structure in wheat: germins." Biochem J 349(Pt 1);309-21. PMID: 10861243

Lane02: Lane BG (2002). "Oxalate, germins, and higher-plant pathogens." IUBMB Life 53(2);67-75. PMID: 12049198

Lane93: Lane BG, Dunwell JM, Ray JA, Schmitt MR, Cuming AC (1993). "Germin, a protein marker of early plant development, is an oxalate oxidase." J Biol Chem 268(17);12239-42. PMID: 8509360

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

Dunwell98: Dunwell JM (1998). "Cupins: a new superfamily of functionally diverse proteins that include germins and plant storage proteins." Biotechnol Genet Eng Rev 15;1-32. PMID: 9573603

Kotsira97: Kotsira VP, Clonis YD (1997). "Oxalate oxidase from barley roots: purification to homogeneity and study of some molecular, catalytic, and binding properties." Arch Biochem Biophys 340(2);239-49. PMID: 9143327

Latendresse13: Latendresse M. (2013). "Computing Gibbs Free Energy of Compounds and Reactions in MetaCyc."

Requena99: Requena L, Bornemann S (1999). "Barley (Hordeum vulgare) oxalate oxidase is a manganese-containing enzyme." Biochem J 343 Pt 1;185-90. PMID: 10493928

Woo00: Woo EJ, Dunwell JM, Goodenough PW, Marvier AC, Pickersgill RW (2000). "Germin is a manganese containing homohexamer with oxalate oxidase and superoxide dismutase activities." Nat Struct Biol 7(11);1036-40. PMID: 11062559

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 Thu Feb 11, 2016, biocyc12.