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MetaCyc Pathway: guanosine nucleotides degradation III
Inferred from experiment

Enzyme View:

Pathway diagram: guanosine nucleotides degradation III

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/AssimilationNucleosides and Nucleotides DegradationPurine Nucleotides DegradationGuanosine Nucleotides Degradation

Some taxa known to possess this pathway include : Drosophila melanogaster, Escherichia coli K-12 substr. MG1655, Homo sapiens, Mus musculus

Expected Taxonomic Range: Bacteria , Metazoa

General Background

The distinction between nucleoside degradation and salvage is not always straight forward. A general rule is that degradation pathways start with the nucleotide forms and convert them to simpler forms, eventually leading to complete mineralization, while salvage pathways start with either the nucleoside or the free base form, and convert those to the nucleotide forms.

Nucleotide recycling is achieved by a combination of both types - a nucleotide is partially degraded via a degradation pathway, but the products are shuttled into a salvage pathway rather then towrds complete mineralization.

About This Pathway

This pathway of guanosine nucleotides degradation begins with the conversion of GMP to guanosine, which is then converted to the free base guanine by the enzyme purine nucleoside phosphorylase (EC Guanine is converted to urate via xanthine by the enzymes guanine deaminase and xanthine oxidase [Hesberg04].

This pathway is very similar to a pathway that occurs in plants and fungi ( guanosine nucleotides degradation II). However, in this pathway guanosine is converted to guanine by the enzyme purine nucleoside phosphorylase (EC while in plants this conversion is catalyzed by the enzyme guanosine deaminase (EC [Roberts03].

Superpathways: purine nucleotides degradation II (aerobic)

Variants: guanosine nucleotides degradation I, guanosine nucleotides degradation II, superpathway of guanosine nucleotides degradation (plants)

Unification Links: EcoCyc:PWY-6608

Created 20-Sep-2010 by Caspi R, SRI International


Hesberg04: Hesberg C, Hansch R, Mendel RR, Bittner F (2004). "Tandem orientation of duplicated xanthine dehydrogenase genes from Arabidopsis thaliana: differential gene expression and enzyme activities." J Biol Chem 279(14);13547-54. PMID: 14726515

Roberts03: Roberts EL (2003). "Guanosine deaminase in human serum and tissue extracts--a reappraisal of the products." Br J Biomed Sci 60(4);197-203. PMID: 14725335

Silva03: Silva RG, Carvalho LP, Oliveira JS, Pinto CA, Mendes MA, Palma MS, Basso LA, Santos DS (2003). "Cloning, overexpression, and purification of functional human purine nucleoside phosphorylase." Protein Expr Purif 27(1);158-64. PMID: 12509998

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

Ahmad68: Ahmad SI, Barth PT, Pritchard RH (1968). "Properties of a mutant of Escherichia coli lacking purine nucleoside phosphorylase." Biochim Biophys Acta 161(2);581-3. PMID: 4875425

Amaya02: Amaya Y, Kawamoto S, Kashima Y, Okamoto K, Nishino T (2002). "Purification and characterization of multiple forms of rat liver xanthine oxidoreductase expressed in baculovirus-insect cell system." J Biochem 132(4);597-606. PMID: 12359075

Asai07: Asai R, Matsumura T, Okamoto K, Igarashi K, Pai EF, Nishino T (2007). "Two mutations convert mammalian xanthine oxidoreductase to highly superoxide-productive xanthine oxidase." J Biochem 141(4);525-34. PMID: 17301076

Bennett03: Bennett EM, Li C, Allan PW, Parker WB, Ealick SE (2003). "Structural basis for substrate specificity of Escherichia coli purine nucleoside phosphorylase." J Biol Chem 278(47);47110-8. PMID: 12937174

Bennett03a: Bennett EM, Anand R, Allan PW, Hassan AE, Hong JS, Levasseur DN, McPherson DT, Parker WB, Secrist JA, Sorscher EJ, Townes TM, Waud WR, Ealick SE (2003). "Designer gene therapy using an Escherichia coli purine nucleoside phosphorylase/prodrug system." Chem Biol 10(12);1173-81. PMID: 14700625

BertoŇ°a14: Bertosa B, Mikleusevic G, Wielgus-Kutrowska B, Narczyk M, Hajnic M, Lescic Asler I, Tomic S, Luic M, Bzowska A (2014). "Homooligomerization is needed for stability: a molecular modelling and solution study of Escherichia coli purine nucleoside phosphorylase." FEBS J 281(7);1860-71. PMID: 24785777

Bezirdzhian86: Bezirdzhian KhO, Kocharian ShM, Akopian ZhI (1986). "[Isolation of the hexameric form of purine nucleoside phosphorylase from E. coli. Comparative study of trimeric and hexameric forms of the enzyme]." Biokhimiia 1986;51(7);1085-92. PMID: 3089333

Bezirdzhian87: Bezirdzhian KhO, Kocharian ShM, Akopian ZhI (1987). "[Hexamere purine nucleoside phosphorylase from Escherichia coli K-12. Kinetic analysis and mechanism of reaction]." Biokhimiia 52(11);1770-6. PMID: 3125860

Bezirdzhian87a: Bezirdzhian KhO, Kocharian ShM, Akopian ZhI (1987). "[Hexameric purine nucleoside phosphorylase II from Escherichia coli K-12. Physico-chemical and catalytic properties and stabilization with substrates]." Biokhimiia 1987;52(10);1624-31. PMID: 3122852

Bianchi03: Bianchi V, Spychala J (2003). "Mammalian 5'-nucleotidases." J Biol Chem 278(47);46195-8. PMID: 12947102

Bideon75: Bideon GM (1975). "Purification and characterization of a cyclic nucleotide-regulated 5'-nucleotidase from potatoe." Biochim Biophys Acta 384(2);443-57. PMID: 235999

Borowiec06: Borowiec A, Lechward K, Tkacz-Stachowska K, Skladanowski AC (2006). "Adenosine as a metabolic regulator of tissue function: production of adenosine by cytoplasmic 5'-nucleotidases." Acta Biochim Pol 53(2);269-78. PMID: 16770441

Boyle88: Boyle JM, Hey Y, Guerts van Kessel A, Fox M (1988). "Assignment of ecto-5'-nucleotidase to human chromosome 6." Hum Genet 81(1);88-92. PMID: 2848759

Bradshaw60: Bradshaw, W.H., Barker, H.A. (1960). "Purification and properties of xanthine dehydrogenase from Clostridium cylindrosporum." J. Biol. Chem. 235(12): 3620-3629.

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

Buxton75: Buxton RS (1975). "Genetic analysis of thymidine-resistant and low-thymine-requiring mutants of Escherichia coli K-12 induced by bacteriophage Mu-1." J Bacteriol 121(2);475-84. PMID: 1089630

Buxton80: Buxton RS, Hammer-Jespersen K, Valentin-Hansen P (1980). "A second purine nucleoside phosphorylase in Escherichia coli K-12. I. Xanthosine phosphorylase regulatory mutants isolated as secondary-site revertants of a deoD mutant." Mol Gen Genet 179(2);331-40. PMID: 7007808

Bzowska00: Bzowska A, Kulikowska E, Shugar D (2000). "Purine nucleoside phosphorylases: properties, functions, and clinical aspects." Pharmacol Ther 88(3);349-425. PMID: 11337031

Bzowska88: Bzowska A, Kulikowska E, Darzynkiewicz E, Shugar D (1988). "Purine nucleoside phosphorylase. Structure-activity relationships for substrate and inhibitor properties of N-1-, N-7-, and C-8-substituted analogues; differentiation of mammalian and bacterial enzymes with N-1-methylinosine and guanosine." J Biol Chem 263(19);9212-7. PMID: 3132457

Calderone04: Calderone V, Forleo C, Benvenuti M, Cristina Thaller M, Maria Rossolini G, Mangani S (2004). "The first structure of a bacterial class B Acid phosphatase reveals further structural heterogeneity among phosphatases of the haloacid dehalogenase fold." J Mol Biol 335(3);761-73. PMID: 14687572

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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
Page generated by Pathway Tools version 19.5 (software by SRI International) on Sat Apr 30, 2016, biocyc14.