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
ec01120  Microbial metabolism in diverse environments
Orthology
K10535  hydroxylamine dehydrogenase
Genes
MCA: MCA0956
MAH: MEALZ_1830(hao)
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
NIT: NAL212_1807 NAL212_2138 NAL212_2750
MSC: BN69_3242
SIL: SPOA0201
MIN: Minf_2434(cccA)
KST: KSMBR1_1220(hdh) KSMBR1_2163(hao_2) KSMBR1_2369(hdh) 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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