Overview for MACiE Entry M0118
EC Number: 184.108.40.206 (A member of the Oxidoreductases, Acting on other nitrogenous compounds as donors, With oxygen as acceptor)
Enzyme Name: urate oxidase
Biological Species: Aspergillus flavus (Fungus)
Catalytic Chain UniprotKB Accession Codes:
Representative PDB Code: 1wrr - URATE OXIDASE FROM ASPERGILLUS FLAVUS COMPLEXED WITH 5-AMINO 6-NITROURACIL (Resolution = 1.64 Å).
Catalytic CATH Codes:
Display structure information
Overall Comment: No cofactor participates in the catalytic reaction . Studies by Imhoff et all/  were performed on the basis of 1uox (superseded) structure. Retailleau et al.  present higher resolution structures and the substrate seems to bind differently. The oligomeric state of this enzyme is homo tetrameric.
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Stepwise Description of the Reaction
|Step 1||Water deprotonates His256D, which deprotonates the urate substrate through Lys10 and Thr57.|
|Step 2||The C2 oxyanion collapses initiating a single electron transfer to dioxygen, which deprotonates water.|
|Step 3||The dioxygen radical undergoes a homolytic reaction and colligates to the urate radical.|
|Step 4||The peroxo group deprotonates urate hydroperoxide, which initiates the elimination of hydrogen peroxide.|
|Step 5||N7 of the substrate deprotonates water, which initiates a nucleophilic attack on the C5 of the substrate in an addition reaction.|
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Catalytic Residues Involved
||Location of Function
- R. D. Imhoff et al. (2003), Biochemistry, 42, 4094-4100. General base catalysis in the urate oxidase reaction: evidence for a novel Thr-Lys catalytic diad.
- P. Retailleau et al. (2004), Acta Cryst., D60, 453-462. Complexed and ligand-free high-resolution structures of urate oxidase (Uox) from Aspergillus flavus: a reassignment of the active-site binding mode.
Homologue information for M0118 (1wrr)
MACiE Homologues (within the PDB)
MACiE Homologues (within UniprotKB/SwissProt)
Links to this entry in other databases