Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 45.63 kDa 
• Atom Count: 3068 
• Modelled Residue Count: 381 
• Deposited Residue Count: 407 
• Unique protein chains: 1

3RP8

Crystal Structure of Klebsiella pneumoniae R204Q HpxO complexed with FAD

• PDB DOI: 10.2210/pdb3RP8/pdb

• Classification: OXIDOREDUCTASE
• Organism(s): Klebsiella pneumoniae subsp. pneumoniae MGH 78578
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 2011-04-26 Released: 2012-05-16 
• Deposition Author(s): Hicks, K.A., O'Leary, S.E., Begley, T.P., Ealick, S.E.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.97 Å
• R-Value Free: 0.229 
• R-Value Work: 0.190 
• R-Value Observed: 0.192 

Literature

Structural and Mechanistic Studies of HpxO, a Novel Flavin Adenine Dinucleotide-Dependent Urate Oxidase from Klebsiella pneumoniae.

Hicks, K.A., O'Leary, S.E., Begley, T.P., Ealick, S.E.

(2013) Biochemistry 52: 477-487

• PubMed: 23259842 
• DOI: 10.1021/bi301262p
• Primary Citation of Related Structures:  
  3RP6, 3RP7, 3RP8


• PubMed Abstract: 
  

HpxO is a flavin-dependent urate oxidase that catalyzes the hydroxylation of uric acid to 5-hydroxyisourate and functions in a novel pathway for purine catabolism found in Klebsiella pneumoniae. We have determined the structures of HpxO with and without uric acid at 2.0 and 2.2 Å, respectively. We have also determined the structure of the R204Q variant at 2.0 Å resolution in the absence of uric acid. The variant structure is very similar to that of wild-type HpxO except for the conformation of Arg103, which interacts with FAD in the variant but not in the wild-type structure. Interestingly, the R204Q variant results in the uncoupling of nicotinamide adenine dinucleotide oxidation from uric acid hydroxylation. This suggests that Arg204 facilitates the deprotonation of uric acid, activating it for the oxygen transfer. On the basis of these data, a mechanism for this reaction consisting of a nucleophilic attack of the urate anion on the flavin hydroperoxide resulting in the formation of 5-hydroxyisourate is proposed.

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Organizational Affiliation: 

Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
flavoprotein monooxygenase	A	407	Klebsiella pneumoniae subsp. pneumoniae MGH 78578	Mutation(s): 1  Gene Names: KPN78578_16330, KPN_01663, hpxO EC: 1.14.13.113
UniProt
Find proteins for A6T923 (Klebsiella pneumoniae subsp. pneumoniae (strain ATCC 700721 / MGH 78578)) Explore A6T923  Go to UniProtKB:  A6T923

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
FAD	B [auth A]	FLAVIN-ADENINE DINUCLEOTIDE C27 H33 N9 O15 P2 VWWQXMAJTJZDQX-UYBVJOGSSA-N
CL	C [auth A]	CHLORIDE ION Cl VEXZGXHMUGYJMC-UHFFFAOYSA-M

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.97 Å
• R-Value Free: 0.229 
• R-Value Work: 0.190 
• R-Value Observed: 0.192 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 67.031	α = 90
b = 68.769	β = 90
c = 81.584	γ = 90

Software Package:

Software Name	Purpose
SCALEPACK	data scaling
PHENIX	refinement
PDB_EXTRACT	data extraction
ADSC	data collection
HKL-2000	data reduction
HKL-2000	data scaling
REFMAC	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2011-04-26 
• Released Date: 2012-05-16 
Deposition Author(s): Hicks, K.A., O'Leary, S.E., Begley, T.P., Ealick, S.E.

Revision History  

• Version 1.0: 2012-05-16
  Type: Initial release
  
• Version 1.1: 2013-01-09
  Changes: Database references
• Version 1.2: 2013-01-23
  Changes: Database references
• Version 1.3: 2013-02-06
  Changes: Database references