PDBsum entry 1r56

Oxidoreductase

PDB id: 1r56

Contents

Protein chains

(+ 2 more) 295 a.a. *

Ligands

PEG ×2

Waters ×334

* Residue conservation analysis

PDB id:

1r56

Name:

Oxidoreductase

Title:

Uncomplexed urate oxidase from aspergillus flavus

Structure:

Uricase. Chain: a, b, c, d, e, f, g, h. Synonym: urate oxidase. Ec: 1.7.3.3

Source:

Aspergillus flavus. Organism_taxid: 5059

Biol. unit:

Tetramer (from PQS)

Resolution:

2.30Å R-factor: 0.162 R-free: 0.214

Authors:

P.Retailleau,N.Colloc'H,T.Prange

Key ref:

P.Retailleau et al. (2004). Complexed and ligand-free high-resolution structures of urate oxidase (Uox) from Aspergillus flavus: a reassignment of the active-site binding mode. Acta Crystallogr D Biol Crystallogr, 60, 453-462. PubMed id: 14993669 DOI: 10.1107/S0907444903029718

Date:

09-Oct-03 Release date: 02-Mar-04

Protein chains

Q00511  (URIC_ASPFL) -  Uricase from Aspergillus flavus

Seq: 302 a.a.

Struc: 295 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.1.7.3.3 - factor independent urate hydroxylase.
• Pathway: AMP Catabolism
• Reaction: urate + O2 + H2O = 5-hydroxyisourate + H2O2
• Cofactor: Copper

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1107/S0907444903029718

Acta Crystallogr D Biol Crystallogr 60:453-462 (2004)

PubMed id: 14993669

Complexed and ligand-free high-resolution structures of urate oxidase (Uox) from Aspergillus flavus: a reassignment of the active-site binding mode.

P.Retailleau, N.Colloc'h, D.Vivarès, F.Bonneté, B.Castro, M.El-Hajji, J.P.Mornon, G.Monard, T.Prangé.

ABSTRACT

High-resolution X-ray structures of the complexes of Aspergillus flavus urate oxidase (Uox) with three inhibitors, 8-azaxanthin (AZA), 9-methyl uric acid (MUA) and oxonic acid (OXC), were determined in an orthorhombic space group (I222). In addition, the ligand-free enzyme was also crystallized in a monoclinic form (P2(1)) and its structure determined. Higher accuracy in the three new enzyme-inhibitor complex structures (Uox-AZA, Uox-MUA and Uox-OXC) with respect to the previously determined structure of Uox-AZA (PDB code 1uox) leads to a reversed position of the inhibitor in the active site of the enzyme. The corrected anchoring of the substrate (uric acid) allows an improvement in the understanding of the enzymatic mechanism of urate oxidase.

Selected figure(s)

Figure 1.
Figure 1 Schematic degradation pathway of uric acid to allantoin through intermediate (2) (5-hydroxyisourate). Only the first step is catalyzed by the enzyme, with H[2]O[2] as the by-product.

Figure 7.
Figure 7 Revised position of 8-azaxanthin relative to the active site of Uox. (a) Original published location of the AZA inhibitor in [212]1uox ; (b) the revised orientation of AZA in the new refined structure (1.8 Å). Both orientations are superimposed on the respective final 2|F[obs]| - |F[calc]| electron-density maps contoured around the inhibitor at 1.75 [213][sigma] .

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2004, 60, 453-462) copyright 2004.

Figures were selected by an automated process.