KEGG   ENZYME: 1.7.2.6Help
Entry
EC 1.7.2.6                  Enzyme                                 

Name
hydroxylamine dehydrogenase;
HAO (ambiguous);
hydroxylamine oxidoreductase (ambiguous);
hydroxylamine oxidase (misleading)
Class
Oxidoreductases;
Acting on other nitrogenous compounds as donors;
With a cytochrome as acceptor
BRITE hierarchy
Sysname
hydroxylamine:ferricytochrome-c oxidoreductase
Reaction(IUBMB)
(1) hydroxylamine + H2O + 4 ferricytochrome c = nitrite + 4 ferrocytochrome c + 5 H+ [RN:R10164];
(2) hydroxylamine + 3 ferricytochrome c = nitric oxide + 3 ferrocytochrome c + 3 H+ [RN:R10165]
Reaction(KEGG)
Substrate
hydroxylamine [CPD:C00192];
H2O [CPD:C00001];
ferricytochrome c [CPD:C00125]
Product
nitrite [CPD:C00088];
ferrocytochrome c [CPD:C00126];
H+ [CPD:C00080];
nitric oxide [CPD:C00533]
Comment
The enzymes from the nitrifying bacterium Nitrosomonas europaea [1,4] and the methylotrophic bacterium Methylococcus capsulatus [5] are hemoproteins with seven c-type hemes and one specialized P-460-type heme per subunit. The enzyme converts hydroxylamine to nitrite via an enzyme-bound nitroxyl intermediate [3]. While nitrite is the main product, the enzyme from Nitrosomonas europaea can produce nitric oxide as well [2].
History
EC 1.7.2.6 created 1972 as EC 1.7.3.4, part transferred 2012 to EC 1.7.2.6
Pathway
ec00910  Nitrogen metabolism
ec01100  Metabolic pathways
ec01120  Microbial metabolism in diverse environments
Orthology
K10535  hydroxylamine dehydrogenase
Genes
MCA: MCA0956
MAH: MEALZ_1830(hao)
MMAI: sS8_3996
NOC: Noc_0892
NHL: Nhal_1085
NWA: Nwat_0758
NTT: TAO_0474(haoA)
SVA: SVA_2722
NEU: NE0962(hao2) NE2044(hao1) NE2339(hao3)
NET: Neut_1672 Neut_1793 Neut_2335
MSC: BN69_3242
SIL: SPOA0201
MIN: Minf_2434(cccA)
KST: KSMBR1_1220(hdh) KSMBR1_2163(hao_2) KSMBR1_2670(hao_3) KSMBR1_3040(hao_4) KSMBR1_3442(hao_7) KSMBR1_3792(hao_8)
NIO: NITINOP_0065(hao)
MOX: DAMO_2473(hao)
 » show all
Taxonomy
Reference
1  [PMID:5758552]
  Authors
Rees MK.
  Title
Studies of the hydroxylamine metabolism of Nitrosomonas europaea. I. Purification of hydroxylamine oxidase.
  Journal
Biochemistry 7:353-66 (1968)
Reference
2  [PMID:497235]
  Authors
Hooper AB, Terry KR
  Title
Hydroxylamine oxidoreductase of Nitrosomonas. Production of nitric oxide from hydroxylamine.
  Journal
Biochim Biophys Acta 571:12-20 (1979)
DOI:10.1016/0005-2744(79)90220-1
Reference
3  [PMID:7117545]
  Authors
Hooper AB, Balny C.
  Title
Reaction of oxygen with hydroxylamine oxidoreductase of Nitrosomonas: fast kinetics.
  Journal
FEBS Lett 144:299-303 (1982)
DOI:10.1016/0014-5793(82)80658-3
Reference
4  [PMID:6289867]
  Authors
Lipscomb JD, Hooper AB.
  Title
Resolution of multiple heme centers of hydroxylamine oxidoreductase from Nitrosomonas. 1. Electron paramagnetic resonance spectroscopy.
  Journal
Biochemistry 21:3965-72 (1982)
Reference
5  [PMID:18650926]
  Authors
Poret-Peterson AT, Graham JE, Gulledge J, Klotz MG
  Title
Transcription of nitrification genes by the methane-oxidizing bacterium, Methylococcus capsulatus strain Bath.
  Journal
ISME J 2:1213-20 (2008)
DOI:10.1038/ismej.2008.71
Other DBs
ExplorEnz - The Enzyme Database: 1.7.2.6
IUBMB Enzyme Nomenclature: 1.7.2.6
ExPASy - ENZYME nomenclature database: 1.7.2.6
BRENDA, the Enzyme Database: 1.7.2.6
CAS: 9075-43-8

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