MetaCyc Reaction:

Superclasses: Reactions Classified By Conversion Type Simple Reactions Chemical Reactions Composite Reactions
Reactions Classified By Substrate Small-Molecule Reactions

EC Number:

Enzymes and Genes:

Stenotrophomonas maltophilia : nucleoside oxidase Inferred from experiment

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

Most BioCyc compounds have been protonated to a reference pH value of 7.3, and some reactions have been computationally balanced for hydrogen by adding free protons. Please see the PGDB Concepts Guide for more information.

Mass balance status: Balanced.

Enzyme Commission Primary Name: nucleoside oxidase

2 inosine + oxygen → 2 5'-dehydroinosine + 2 H2O ,
2 5'-dehydroinosine + oxygen → 2 9-riburonosylhypoxanthine + 2 H+

Standard Gibbs Free Energy (ΔrG in kcal/mol): -113.9811 Inferred by computational analysis [Latendresse13]

Enzyme Commission Summary:
Other purine and pyrimidine nucleosides (as well as 2'-deoxynucleosides) are substrates, but ribose and nucleotides are not substrates.

The overall reaction takes place in two separate steps, with the 5'-dehydro nucleoside being released from the enzyme to serve as substrate for the second reaction.

The two reactions are:

2 inosine + oxygen → 2 5'-dehydroinosine + 2 H2O

2 5'-dehydroinosine + oxygen → 2 9-riburonosylhypoxanthine + 2 H+

This enzyme differs from EC, nucleoside oxidase (H2O2-forming), as it produces water rather than hydrogen peroxide.

Citations: [Isono89a]

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Unification Links: KEGG:R05821

Relationship Links: BRENDA:EC: , ENZYME:EC: , IUBMB-ExplorEnz:EC:

Revised 05-Aug-2009 by Caspi R , SRI International


Isono89a: Isono, Y, Sudo, T., Hoshino, M. (1989). "Purification and reaction of a new enzyme, nucleoside oxidase." Agric. Biol. Chem. 53:1663-1669.

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

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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 SRI International Pathway Tools version 19.0 on Sun Oct 4, 2015, biocyc13.