2VMJ

Type 1 Copper-Binding Loop of Nitrite Reductase mutant: 130- CAPEGMVPWHVVSGM-144 to 130-CTPHPFM-136

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.184 

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This is version 1.2 of the entry. See complete history. 


Literature

The Importance of the Long Type 1 Copper-Binding Loop of Nitrite Reductase for Structure and Function.

Sato, K., Firbank, S.J., Li, C., Banfield, M.J., Dennison, C.

(2008) Chemistry 14: 5820

  • DOI: 10.1002/chem.200701997
  • Primary Citation of Related Structures:  
    2VN3, 2VMJ

  • PubMed Abstract: 

    • The long 15-residue type 1 copper-binding loop of nitrite reductase has been replaced with that from the cupredoxin amicyanin (7 residues). This sizable loop contraction does not have a significant effect on the spectroscopy, and therefore, the struc ...

    The long 15-residue type 1 copper-binding loop of nitrite reductase has been replaced with that from the cupredoxin amicyanin (7 residues). This sizable loop contraction does not have a significant effect on the spectroscopy, and therefore, the structures of both the type 1 and type 2 Cu(II) sites. The crystal structure of this variant with Zn(II) at both the type 1 and type 2 sites has been determined. The coordination geometry of the type 2 site is almost identical to that found in the wild-type protein. However, the structure of the type 1 centre changes significantly upon metal substitution, which is an unusual feature for this class of site. The positions of most of the coordinating residues are altered of which the largest difference was observed for the coordinating His residue in the centre of the mutated loop. This ligand moves away from the active site, which results in a more open metal centre with a coordinating water molecule. Flexibility has been introduced into this region of the protein. The 200 mV increase in the reduction potential of the type 1 copper site indicates that structural changes upon reduction must stabilise the cuprous form. The resulting unfavourable driving force for electron transfer between the two copper sites, and an increased reorganisation energy for the type 1 centre, contribute to the loop variant having very little nitrite reductase activity. The extended type 1 copper-binding loop of this enzyme makes a number of interactions that are important for maintaining quaternary structure.

    Organizational Affiliation: 

    Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH (UK).



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
DISSIMILATORY COPPER-CONTAINING NITRITE REDUCTASEA329Achromobacter xylosoxidansMutation(s): 0 
Gene Names: nir, nirK, ERS451415_02178
EC: 1.7.2.1
Find proteins for O68601 (Alcaligenes xylosoxydans xylosoxydans)
Explore O68601 
Go to UniProtKB:  O68601
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
EPE
Query on EPE
Download Ideal Coordinates CCD File 
A
4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID
C8 H18 N2 O4 S
JKMHFZQWWAIEOD-UHFFFAOYSA-N		 Ligand Interaction
ZN
Query on ZN
Download Ideal Coordinates CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N		 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.181 
  • R-Value Observed: 0.184 
  • Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 89.813α = 90
b = 89.813β = 90
c = 143.099γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling
MOLREPphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-12-23
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance