DB code: D00050

CATH domain 1.10.780.10 : Hydroxylamine Oxidoreductase; Chain A, domain 1 Catalytic domain
1.20.850.10 : Hydroxylamine Oxidoreductase; Chain A, domain 2 Catalytic domain
E.C. 1.7.3.4
CSA 1fgj
M-CSA 1fgj
MACiE

CATH domain Related DB codes (homologues)

Uniprot Enzyme Name
UniprotKB Protein name Synonyms RefSeq
Q50925 Hydroxylamine oxidoreductase
HAO
EC 1.7.2.6
NP_841035.1 (Protein)
NC_004757.1 (DNA/RNA sequence)
NP_842054.1 (Protein)
NC_004757.1 (DNA/RNA sequence)
NP_842336.1 (Protein)
NC_004757.1 (DNA/RNA sequence)

KEGG enzyme name
cf. EC 1.7.99.8, hydroxylamine oxidoreductase)
hydroxylamine oxidase
HAO (ambiguous
cf. EC 1.7.99.8, hydroxylamine oxidoreductase)
hydroxylamine oxidoreductase (ambiguous

UniprotKB: Accession Number Entry name Activity Subunit Subcellular location Cofactor
Q50925 HAO_NITEU Hydroxylamine + O(2) = nitrite + H(2)O. Homotrimer. Periplasm. Binds 8 heme groups per subunit. One heme group a p-460 type, the remaining 7 are c-type.

KEGG Pathways
Map code Pathways E.C.
MAP00910 Nitrogen metabolism

Compound table
Cofactors Substrates Products Intermediates
KEGG-id C00032 C00192 C00007 C00088 C00001
E.C.
Compound Heme Hydroxylamine O2 Nitrite H2O
Type aromatic ring (with nitrogen atoms),carboxyl group,heavy metal amine group others others H2O
ChEBI 17627
26355
15429
15379
26689
27140
25567
15377
PubChem 787
977
24529
22247451
962
1fgjA01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:4xHEM,HEC Unbound Unbound Unbound Unbound
1fgjB01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:3xHEM Unbound Unbound Unbound Unbound
1fgjA02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:4xHEM,HEC Unbound Unbound Unbound Unbound
1fgjB02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain Bound:3xHEM Unbound Unbound Unbound Unbound

Reference for Active-site residues
resource references E.C.

Active-site residues
PDB Catalytic residues Cofactor-binding residues Modified residues Main-chain involved in catalysis Comment
1fgjA01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain HIS 83;HIS 160(Fe1);HIS 149;HIS 246(Fe2);HIS 99;HIS 176(Fe3);HIS 233(Fe4);HIS 243(Fe5);HIS 204(Fe6)
1fgjB01 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain HIS 83;HIS 160(Fe1);HIS 149;HIS 246(Fe2);HIS 99;HIS 176(Fe3);HIS 233(Fe4);HIS 243(Fe5);HIS 204(Fe6)
1fgjA02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain HIS 323(Fe5);HIS 263(Fe6);HIS 314;HIS 459(Fe7);HIS 279;HIS 364(Fe8)
1fgjB02 Pdbj logo s Rasmollogo id Rasmollogo chain Mmcif id Mmcif chain HIS 323(Fe5);HIS 263(Fe6);HIS 314;HIS 459(Fe7);HIS 279;HIS 364(Fe8)

References for Catalytic Mechanism
References Sections No. of steps in catalysis
[2]
p.282-283, Fig.6

References
[1]
Resource
Comments
Medline ID
PubMed ID 1783597
Journal J Biochem (Tokyo)
Year 1991
Volume 110
Pages 681-2
Authors Mikami T, Tanaka N, Sato T, Moriyama H, Numata M, Fujiwara T, Fukumori Y, Yamanaka T, Sato M, Kakiuchi K, et al
Title Crystallization and preliminary X-ray studies of hydroxylamine oxidoreductase from Nitrosomonas europaea.
Related PDB
Related UniProtKB
[2]
Resource
Comments X-RAY CRYSTALLOGRAPHY (2.8 ANGSTROMS)
Medline ID 97249290
PubMed ID 9095195
Journal Nat Struct Biol
Year 1997
Volume 4
Pages 276-84
Authors Igarashi N, Moriyama H, Fujiwara T, Fukumori Y, Tanaka N
Title The 2.8 A structure of hydroxylamine oxidoreductase from a nitrifying chemoautotrophic bacterium, Nitrosomonas europaea.
Related PDB 1fgj
Related UniProtKB Q50925
[3]
Resource
Comments
Medline ID
PubMed ID 9425072
Journal Biochemistry
Year 1998
Volume 37
Pages 523-9
Authors Arciero DM, Golombek A, Hendrich MP, Hooper AB
Title Correlation of optical and EPR signals with the P460 heme of hydroxylamine oxidoreductase from Nitrosomonas europaea.
Related PDB
Related UniProtKB
[4]
Resource
Comments
Medline ID
PubMed ID 11457010
Journal J Am Chem Soc
Year 2001
Volume 123
Pages 2997-3005
Authors Hendrich MP, Petasis D, Arciero DM, Hooper AB
Title Correlations of structure and electronic properties from EPR spectroscopy of hydroxylamine oxidoreductase.
Related PDB
Related UniProtKB

Comments
According to the literature [2], this enzyme catalyzes the following reactions:
(A) Oxygenation of NH2OH by O2, producing HNO2 and H2O, at heme-P460 (HEC in 1fgi):
(B) Electron transfer from heme-P460 to heme-6:
(C) Electron transfer from heme-P460 to heme-7:
(D) Electron transfer from heme-6 to heme-5:
(E) Electron transfer from heme-5 to heme-3:
(F) Electron transfer from heme-3 to heme-2:
(G) Electron transfer from heme-2 to heme-1:
(H) Electron transfer from heme-7 to heme-8:
(I) Electron transfer from heme-8 to heme-2 (of adjacent subunit):
(J) Electron transfer from heme-1 to cytochrome-c554:

Created Updated
2004-03-24 2009-02-26