EC |
1.7.3.3 |
Accepted name: |
factor-independent urate hydroxylase |
Reaction: |
urate + O2 + H2O = 5-hydroxyisourate + H2O2 |
|
For diagram of AMP catabolism, click here |
Other name(s): |
uric acid oxidase; uricase; uricase II; urate oxidase |
Systematic name: |
urate:oxygen oxidoreductase |
Comments: |
This enzyme was previously thought to be a copper protein, but it is now known that the enzymes from soy bean (Glycine max), the mould Aspergillus flavus and Bacillus subtilis contains no copper nor any other transition-metal ion. The 5-hydroxyisourate formed decomposes spontaneously to form allantoin and CO2, although there is an enzyme-catalysed pathway in which EC 3.5.2.17, hydroxyisourate hydrolase, catalyses the first step. The enzyme is different from EC 1.14.13.113 (FAD-dependent urate hydroxylase). |
Links to other databases: |
BRENDA, EAWAG-BBD, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9002-12-4 |
References: |
1. |
London, M. and Hudson, P.B. Purification and properties of solubilized uricase. Biochim. Biophys. Acta 21 (1956) 290–298. [DOI] [PMID: 13363909] |
2. |
Mahler, H.R., Hübscher, G. and Baum, H. Studies on uricase. I. Preparation, purification, and properties of a cuproprotein. J. Biol. Chem. 216 (1955) 625–641. [PMID: 13271340] |
3. |
Robbins, K.C., Barnett, E.L. and Grant, N.H. Partial purification of porcine liver uricase. J. Biol. Chem. 216 (1955) 27–35. [PMID: 13252004] |
4. |
Kahn, K. and Tipton, P.A. Spectroscopic characterization of intermediates in the urate oxidase reaction. Biochemistry 37 (1998) 11651–11659. [DOI] [PMID: 9709003] |
5. |
Colloc'h, N., el Hajji, M., Bachet, B., L'Hermite, G., Schiltz, M., Prange, T., Castro, B. and Mornon, J.-P. Crystal structure of the protein drug urate oxidase-inhibitor complex at 2.05 Å resolution. Nat. Struct. Biol. 4 (1997) 947–952. [PMID: 9360612] |
6. |
Imhoff, R.D., Power, N.P., Borrok, M.J. and Tipton, P.A. General base catalysis in the urate oxidase reaction: evidence for a novel Thr-Lys catalytic diad. Biochemistry 42 (2003) 4094–4100. [DOI] [PMID: 12680763] |
|
[EC 1.7.3.3 created 1961, modified 2002, modified 2005, modified 2010] |
|
|
|
|
EC |
1.14.13.113 |
Accepted name: |
FAD-dependent urate hydroxylase |
Reaction: |
urate + NADH + H+ + O2 = 5-hydroxyisourate + NAD+ + H2O |
Other name(s): |
HpxO enzyme; FAD-dependent urate oxidase; urate hydroxylase |
Systematic name: |
urate,NADH:oxygen oxidoreductase (5-hydroxyisourate-forming) |
Comments: |
A flavoprotein. The reaction is part of the purine catabolic pathway in the bacterium Klebsiella pneumoniae. The enzyme is different from EC 1.7.3.3, factor-independent urate hydroxylase, found in most plants, which produces hydrogen peroxide. The product of the enzyme is a substrate for EC 3.5.2.17, hydroxyisourate hydrolase. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB |
References: |
1. |
O'Leary, S.E., Hicks, K.A., Ealick, S.E. and Begley, T.P. Biochemical characterization of the HpxO enzyme from Klebsiella pneumoniae, a novel FAD-dependent urate oxidase. Biochemistry 48 (2009) 3033–3035. [DOI] [PMID: 19260710] |
|
[EC 1.14.13.113 created 2010] |
|
|
|
|
EC |
1.14.13.212 |
Accepted name: |
1,3,7-trimethyluric acid 5-monooxygenase |
Reaction: |
1,3,7-trimethylurate + NADH + H+ + O2 = 1,3,7-trimethyl-5-hydroxyisourate + NAD+ + H2O |
Glossary: |
isourate = 1,3,5,7-tetrahydropurine-2,6,8-trione |
Other name(s): |
tmuM (gene name) |
Systematic name: |
1,3,7-trimethylurate,NADH:oxygen oxidoreductase (1,3,7-trimethyl-5-hydroxyisourate-forming) |
Comments: |
The enzyme, characterized from the bacterium Pseudomonas sp. CBB1, is part of the bacterial C-8 oxidation-based caffeine degradation pathway. The product decomposes spontaneously to a racemic mixture of 3,6,8-trimethylallantoin. The enzyme shows no acitivity with urate. cf. EC 1.14.13.113, FAD-dependent urate hydroxylase. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc |
References: |
1. |
Mohanty, S.K., Yu, C.L., Das, S., Louie, T.M., Gakhar, L. and Subramanian, M. Delineation of the caffeine C-8 oxidation pathway in Pseudomonas sp. strain CBB1 via characterization of a new trimethyluric acid monooxygenase and genes involved in trimethyluric acid metabolism. J. Bacteriol. 194 (2012) 3872–3882. [DOI] [PMID: 22609920] |
2. |
Summers, R.M., Mohanty, S.K., Gopishetty, S. and Subramanian, M. Genetic characterization of caffeine degradation by bacteria and its potential applications. Microb. Biotechnol. 8 (2015) 369–378. [DOI] [PMID: 25678373] |
|
[EC 1.14.13.212 created 2016] |
|
|
|
|
EC |
3.5.2.17 |
Accepted name: |
hydroxyisourate hydrolase |
Reaction: |
5-hydroxyisourate + H2O = 5-hydroxy-2-oxo-4-ureido-2,5-dihydro-1H-imidazole-5-carboxylate |
|
For diagram of AMP catabolism, click here |
Other name(s): |
HIUHase; 5-hydroxyisourate hydrolase |
Systematic name: |
5-hydroxyisourate amidohydrolase |
Comments: |
The reaction is the first stage in the conversion of 5-hydroxyisourate into S-allantoin. This reaction will also occur spontaneously but more slowly. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 255885-20-2 |
References: |
1. |
Raychaudhuri, A. and Tipton, P.A. A familiar motif in a new context: the catalytic mechanism of hydroxyisourate hydrolase. Biochemistry 42 (2003) 6848–6852. [DOI] [PMID: 12779339] |
2. |
Raychaudhuri, A. and Tipton, P.A. Cloning and expression of the gene for soybean hydroxyisourate hydrolase. Localization and implications for function and mechanism. Plant Physiol. 130 (2002) 2061–2068. [DOI] [PMID: 12481089] |
3. |
Sarma, A.D., Serfozo, P., Kahn, K. and Tipton, P.A. Identification and purification of hydroxyisourate hydrolase, a novel ureide-metabolizing enzyme. J. Biol. Chem. 274 (1999) 33863–33865. [DOI] [PMID: 10567345] |
|
[EC 3.5.2.17 created 2004] |
|
|
|
|