2DWT

Cu-containing nitrite reductase at pH 6.0 with bound nitrite


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.199 

Starting Model: experimental
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This is version 1.4 of the entry. See complete history


Literature

pH Dependence of Copper Geometry, Reduction Potential, and Nitrite Affinity in Nitrite Reductase

Jacobson, F.Pistorius, A.Farkas, D.De Grip, W.Hansson, O.Sjolin, L.Neutze, R.

(2007) J Biol Chem 282: 6347-6355

  • DOI: https://doi.org/10.1074/jbc.M605746200
  • Primary Citation of Related Structures:  
    2DWS, 2DWT, 2DY2

  • PubMed Abstract: 

    Many properties of copper-containing nitrite reductase are pH-dependent, such as gene expression, enzyme activity, and substrate affinity. Here we use x-ray diffraction to investigate the structural basis for the pH dependence of activity and nitrite affinity by examining the type 2 copper site and its immediate surroundings in nitrite reductase from Rhodobacter sphaeroides 2.4.3. At active pH the geometry of the substrate-free oxidized type 2 copper site shows a near perfect tetrahedral geometry as defined by the positions of its ligands. At higher pH values the most favorable copper site geometry is altered toward a more distorted tetrahedral geometry whereby the solvent ligand adopts a position opposite to that of the His-131 ligand. This pH-dependent variation in type 2 copper site geometry is discussed in light of recent computational results. When co-crystallized with substrate, nitrite is seen to bind in a bidentate fashion with its two oxygen atoms ligating the type 2 copper, overlapping with the positions occupied by the solvent ligand in the high and low pH structures. Fourier transformation infrared spectroscopy is used to assign the pH dependence of the binding of nitrite to the active site, and EPR spectroscopy is used to characterize the pH dependence of the reduction potential of the type 2 copper site. Taken together, these spectroscopic and structural observations help to explain the pH dependence of nitrite reductase, highlighting the subtle relationship between copper site geometry, nitrite affinity, and enzyme activity.


  • Organizational Affiliation

    Department of Chemical and Biological Engineering, Chalmers University of Technology, Box 462, SE-40530 Göteborg, Sweden.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Copper-containing nitrite reductase329Cereibacter sphaeroidesMutation(s): 0 
Gene Names: nirK
EC: 1.7.2.1
UniProt
Find proteins for Q53239 (Cereibacter sphaeroides (strain ATCC 17025 / ATH 2.4.3))
Explore Q53239 
Go to UniProtKB:  Q53239
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ53239
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.235 
  • R-Value Work: 0.199 
  • Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 74.74α = 90
b = 74.74β = 90
c = 153.146γ = 120
Software Package:
Software NamePurpose
SCALAdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction
MAR345data collection
MOSFLMdata reduction
CCP4data scaling
MOLREPphasing

Structure Validation

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Entry History 

Deposition Data

  • Released Date: 2006-12-05 
  • Deposition Author(s): Jacobson, F.

Revision History  (Full details and data files)

  • Version 1.0: 2006-12-05
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Advisory, Data collection, Refinement description
  • Version 1.4: 2023-10-25
    Changes: Advisory, Data collection, Database references, Derived calculations, Refinement description