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:||Biosynthesis → Secondary Metabolites Biosynthesis|
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.
Numerous filamentous fungi, including the food biotechnology fungus Aspergillus niger, the opportunistic human pathogen Aspergillus fumigatus, the phytopathogenic fungi Botrytis cinerea and Sclerotinia sclerotiorum, as well as many brown-rot and white-rot basidiomycetes, are able to efficiently produce large quantities of oxalate [Kubicek88, Gadd99]. It is known that oxalate secretion is associated with fungal pathogenesis [Kubicek88, Nakagawa99, Guimaraes04, Kirkland05]. In the wood-rotting fungus Fomitopsis palustris oxalate is formed as the product of glucose metabolism via oxaloacetate [Munir01].
There are three potential routes for production of oxalate in fungi: oxidation of glyoxylate (EC 220.127.116.11) [Balmforth84], oxidation of glycolaldehyde [Hammel94], and hydrolysis of oxaloacetate (EC 18.104.22.168) [Lenz76]. However, the results of studies of 14CO2 incorporation into the metabolite pools of Aspergillus niger indicated that oxalate is derived from oxaloacetate [Kubicek88]. Thus, while oxalate is generated through several different biochemical pathways in fungi, oxaloacetate acetylhydrolase-catalyzed hydrolytic cleavage of oxaloacetate is believed to be an especially important route [Kubicek88].
The enzymatic formation of oxalate and acetate from oxaloacetate has been first reported in 1956, from the mold Aspergillus niger [Hayaishi56]. That enzyme was not purified at the time, but it was shown that it required manganese. In subsequent studies the enzyme was partially purified [Lenz76] and a mutant was obtained [vandenHombergh95]. The OAHA gene encoding the enzyme has been identified in Aspergillus niger and cloned from the fungus Botrytis cinerea [Han07].
While the enzyme is most common in fungi, its activity has been described in some plants, especially those of the genus Oxalis [Millerd63, Chang68, Lu05a, Weir06]. The petal death protein from the flowering plant Dianthus caryophyllus has been purified and shown to possess oxaloacetate acetylhydrolase activity in addition to 2-alkylmalate C-C bond lyase activity [Teplyakov05].
Hammel94: Hammel KE, Mozuch MD, Jensen KA, Kersten PJ (1994). "H2O2 recycling during oxidation of the arylglycerol beta-aryl ether lignin structure by lignin peroxidase and glyoxal oxidase." Biochemistry 33(45);13349-54. PMID: 7947743
Han07: Han Y, Joosten HJ, Niu W, Zhao Z, Mariano PS, McCalman M, van Kan J, Schaap PJ, Dunaway-Mariano D (2007). "Oxaloacetate hydrolase, the C-C bond lyase of oxalate secreting fungi." J Biol Chem 282(13);9581-90. PMID: 17244616
Lu05a: Lu Z, Feng X, Song L, Han Y, Kim A, Herzberg O, Woodson WR, Martin BM, Mariano PS, Dunaway-Mariano D (2005). "Diversity of function in the isocitrate lyase enzyme superfamily: the Dianthus caryophyllus petal death protein cleaves alpha-keto and alpha-hydroxycarboxylic acids." Biochemistry 44(50);16365-76. PMID: 16342929
Munir01: Munir E, Yoon JJ, Tokimatsu T, Hattori T, Shimada M (2001). "A physiological role for oxalic acid biosynthesis in the wood-rotting basidiomycete Fomitopsis palustris." Proc Natl Acad Sci U S A 98(20);11126-30. PMID: 11553780
Teplyakov05: Teplyakov A, Liu S, Lu Z, Howard A, Dunaway-Mariano D, Herzberg O (2005). "Crystal structure of the petal death protein from carnation flower." Biochemistry 44(50);16377-84. PMID: 16342930
vandenHombergh95: van den Hombergh JP, van de Vondervoort PJ, van der Heijden NC, Visser J (1995). "New protease mutants in Aspergillus niger result in strongly reduced in vitro degradation of target proteins; genetical and biochemical characterization of seven complementation groups." Curr Genet 28(4);299-308. PMID: 8590475
Weir06: Weir TL, Bais HP, Stull VJ, Callaway RM, Thelen GC, Ridenour WM, Bhamidi S, Stermitz FR, Vivanco JM (2006). "Oxalate contributes to the resistance of Gaillardia grandiflora and Lupinus sericeus to a phytotoxin produced by Centaurea maculosa." Planta 223(4);785-95. PMID: 16395587
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