3NN1

Structure of chlorite dismutase from Candidatus Nitrospira defluvii in complex with imidazole


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.180 
  • R-Value Observed: 0.181 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural and functional characterisation of the chlorite dismutase from the nitrite-oxidizing bacterium "Candidatus Nitrospira defluvii": Identification of a catalytically important amino acid residue

Kostan, J.Sjoeblom, B.Maixner, F.Mlynek, G.Furtmueller, P.G.Obinger, C.Wagner, M.Daims, H.Djinovic-Carugo, K.

(2010) J Struct Biol 172: 331-342

  • DOI: 10.1016/j.jsb.2010.06.014
  • Primary Citation of Related Structures:  
    3NN1, 3NN2, 3NN3, 3NN4

  • PubMed Abstract: 
  • Chlorite dismutase (Cld) is a unique heme enzyme which transforms chlorite to chloride and molecular oxygen (reaction: ClO(2)(-)→Cl(-)+O(2)). Since bacteria with Cld play significant roles in the bioremediation of industrially contaminated sites and also in wastewater treatment, it is of high interest to understand the molecular mechanism of chlorite detoxification ...

    Chlorite dismutase (Cld) is a unique heme enzyme which transforms chlorite to chloride and molecular oxygen (reaction: ClO(2)(-)→Cl(-)+O(2)). Since bacteria with Cld play significant roles in the bioremediation of industrially contaminated sites and also in wastewater treatment, it is of high interest to understand the molecular mechanism of chlorite detoxification. Here we investigate a highly active Cld from Candidatus Nitrospira defluvii (NdCld), a key nitrifier in biological wastewater treatment, using a comprehensive structural, biochemical and bioinformatics approach. We determined the crystal structure of Cld from Candidatus Nitrospira defluvii and showed that functional NdCld is a homopentamer possessing a fold found in other Clds and Cld-like enzymes. To investigate the Cld function in more detail, site-directed mutagenesis of a catalytically important residue (Arg173) was performed and two enzyme mutants were structurally and biochemically characterized. Arginine 173 is demonstrated to play a key role in (i) controlling of ligand and substrate access and binding and (ii) in chlorite dismutation reaction. The flexible residue modulates the electrostatic potential and size of the active site entrance and might be involved in keeping transiently formed hypochlorite in place for final molecular oxygen and chloride formation. Furthermore, using a structure-based sequence alignment, we show that the residue corresponding to Arg173 is conserved in all known active forms of Cld and propose it as a marker for Cld activity in yet uncharacterized Cld-like proteins. Finally, our analysis indicates that all Clds and Cld-like enzymes employ a non-covalently bound heme as a cofactor.


    Organizational Affiliation

    Department for Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, A-1030 Vienna, Austria.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Chlorite dismutase ABCDE241Nitrospira defluviiMutation(s): 0 
Gene Names: cldcld1NIDE1387
EC: 1.13.11.49
Find proteins for B3U4H7 (Nitrospira defluvii)
Explore B3U4H7 
Go to UniProtKB:  B3U4H7
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HEM
Query on HEM

Download Ideal Coordinates CCD File 
A, B, C, D, E
PROTOPORPHYRIN IX CONTAINING FE
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
PO4
Query on PO4

Download Ideal Coordinates CCD File 
A, B, C, D, E
PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
IMD
Query on IMD

Download Ideal Coordinates CCD File 
A, B, C, D, E
IMIDAZOLE
C3 H5 N2
RAXXELZNTBOGNW-UHFFFAOYSA-O
 Ligand Interaction
EDO
Query on EDO

Download Ideal Coordinates CCD File 
A, B, C, D, E
1,2-ETHANEDIOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.180 
  • R-Value Observed: 0.181 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 145.67α = 90
b = 145.67β = 90
c = 136.44γ = 120
Software Package:
Software NamePurpose
DNAdata collection
MOLREPphasing
REFMACrefinement
XDSdata reduction
XSCALEdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-07-28
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance