Entry |
|
Name |
hydroxylamine oxidase (cytochrome);
HAO (ambiguous);
hydroxylamine oxidoreductase (ambiguous);
hydroxylamine oxidase (misleading)
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Class |
Oxidoreductases;
Acting on other nitrogenous compounds as donors;
With oxygen as acceptor
 |
Sysname |
hydroxylamine:oxygen oxidoreductase
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Reaction(IUBMB) |
hydroxylamine + O2 = nitrite + H2O + H+ (overall reaction) [RN: R10230];
(1a) hydroxylamine + 2 ferricytochrome c = nitroxyl + 2 ferrocytochrome c + 2 H+ [RN: R10913];
(1b) nitroxyl + 2 ferrocytochrome c + O2 + H+ = nitrite + 2 ferricytochrome c + H2O (spontaneous) [RN: R10914]
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Reaction(KEGG) |
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Substrate |
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Product |
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Comment |
The enzyme from the heterotrophic nitrifying bacterium Paracoccus denitrificans contains three to five non-heme, non-iron-sulfur iron atoms and interacts with cytochrome c556 and pseudoazurin [2,3]. Under anaerobic conditions in vitro only nitrous oxide is formed [3]. Presumably nitroxyl is released and combines with a second nitroxyl to give nitrous oxide and water. When oxygen is present, nitrite is formed.
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History |
EC 1.7.3.6 created 1972 as EC 1.7.3.4, part transferred 2013 to EC 1.7.3.6, modified 2015
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Reference |
1 |
Authors |
Kurokawa, M, Fukumori, Y and Yamanaka, T |
Title |
A hydroxylamine - cytochrome c reductase occurs in the heterotrophic nitrifier Arthrobacter globiformis. |
Journal |
Plant Cell Physiol 26 (1985) 1439-1442. |
Reference |
|
Authors |
Wehrfritz JM, Reilly A, Spiro S, Richardson DJ |
Title |
Purification of hydroxylamine oxidase from Thiosphaera pantotropha. Identification of electron acceptors that couple heterotrophic nitrification to aerobic denitrification. |
Journal |
FEBS. Lett. 335 (1993) 246-50. |
Reference |
|
Authors |
Moir JW, Wehrfritz JM, Spiro S, Richardson DJ |
Title |
The biochemical characterization of a novel non-haem-iron hydroxylamine oxidase from Paracoccus denitrificans GB17. |
Journal |
Biochem. J. 319 ( Pt 3) (1996) 823-7. |
Reference |
|
Authors |
Wehrfritz J, Carter JP, Spiro S, Richardson DJ |
Title |
Hydroxylamine oxidation in heterotrophic nitrate-reducing soil bacteria and purification of a hydroxylamine-cytochrome c oxidoreductase from a Pseudomonas species. |
Journal |
Arch. Microbiol. 166 (1996) 421-4. |
Other DBs |
ExplorEnz - The Enzyme Database: IUBMB Enzyme Nomenclature: ExPASy - ENZYME nomenclature database: BRENDA, the Enzyme Database: CAS: 9075-43-8 |