1ET5

CRYSTAL STRUCTURE OF NITRITE REDUCTASE ASP98ASN MUTANT FROM ALCALIGENES FAECALIS S-6


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.185 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Catalytic roles for two water bridged residues (Asp-98 and His-255) in the active site of copper-containing nitrite reductase.

Boulanger, M.J.Kukimoto, M.Nishiyama, M.Horinouchi, S.Murphy, M.E.

(2000) J.Biol.Chem. 275: 23957-23964

  • DOI: 10.1074/jbc.M001859200
  • Primary Citation of Related Structures:  1ET7, 1ET8

  • PubMed Abstract: 
  • Two active site residues, Asp-98 and His-255, of copper-containing nitrite reductase (NIR) from Alcaligenes faecalis have been mutated to probe the catalytic mechanism. Three mutations at these two sites (D98N, H255D, and H255N) result in large reduc ...

    Two active site residues, Asp-98 and His-255, of copper-containing nitrite reductase (NIR) from Alcaligenes faecalis have been mutated to probe the catalytic mechanism. Three mutations at these two sites (D98N, H255D, and H255N) result in large reductions in activity relative to native NIR, suggesting that both residues are involved intimately in the reaction mechanism. Crystal structures of these mutants have been determined using data collected to better than 1. 9-A resolution. In the native structure, His-255 Nepsilon2 forms a hydrogen bond through a bridging water molecule to the side chain of Asp-98, which also forms a hydrogen bond to a water or nitrite oxygen ligated to the active site copper. In the D98N mutant, reorientation of the Asn-98 side chain results in the loss of the hydrogen bond to the copper ligand water, consistent with a negatively charged Asp-98 directing the binding and protonation of nitrite in the native enzyme. An additional solvent molecule is situated between residues 255 and the bridging water in the H255N and H255D mutants and likely inhibits nitrite binding. The interaction of His-255 with the bridging water appears to be necessary for catalysis and may donate a proton to reaction intermediates in addition to Asp-98.


    Organizational Affiliation

    Departments of Biochemistry and Molecular Biology and of Microbiology and Immunology, University of British Columbia, Vancouver V6T 1Z3, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
NITRITE REDUCTASE
A
341Alcaligenes faecalisGene Names: nirK (nir)
EC: 1.7.2.1
Find proteins for P38501 (Alcaligenes faecalis)
Go to UniProtKB:  P38501
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
CU
Query on CU

Download SDF File 
Download CCD File 
A
COPPER (II) ION
Cu
JPVYNHNXODAKFH-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.185 
  • Space Group: H 3
Unit Cell:
Length (Å)Angle (°)
a = 127.940α = 90.00
b = 127.940β = 90.00
c = 66.426γ = 120.00
Software Package:
Software NamePurpose
DENZOdata reduction
CNSrefinement
AMoREphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-08-24
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance