1RSV

azide complex of the diferrous E238A mutant R2 subunit of ribonucleotide reductase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.182 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Restoring proper radical generation by azide binding to the iron site of the E238A mutant R2 protein of ribonucleotide reductase from Escherichia coli.

Assarsson, M.Andersson, M.E.Hogbom, M.Persson, B.O.Sahlin, M.Barra, A.L.Sjoberg, B.M.Nordlund, P.Graslund, A.

(2001) J.Biol.Chem. 276: 26852-26859

  • DOI: 10.1074/jbc.M008190200

  • PubMed Abstract: 
  • The enzyme activity of Escherichia coli ribonucleotide reductase requires the presence of a stable tyrosyl free radical and diiron center in its smaller R2 component. The iron/radical site is formed in a reconstitution reaction between ferrous iron a ...

    The enzyme activity of Escherichia coli ribonucleotide reductase requires the presence of a stable tyrosyl free radical and diiron center in its smaller R2 component. The iron/radical site is formed in a reconstitution reaction between ferrous iron and molecular oxygen in the protein. The reaction is known to proceed via a paramagnetic intermediate X, formally a Fe(III)-Fe(IV) state. We have used 9.6 GHz and 285 GHz EPR to investigate intermediates in the reconstitution reaction in the iron ligand mutant R2 E238A with or without azide, formate, or acetate present. Paramagnetic intermediates, i.e. a long-living X-like intermediate and a transient tyrosyl radical, were observed only with azide and under none of the other conditions. A crystal structure of the mutant protein R2 E238A/Y122F with a diferrous iron site complexed with azide was determined. Azide was found to be a bridging ligand and the absent Glu-238 ligand was compensated for by azide and an extra coordination from Glu-204. A general scheme for the reconstitution reaction is presented based on EPR and structure results. This indicates that tyrosyl radical generation requires a specific ligand coordination with 4-coordinate Fe1 and 6-coordinate Fe2 after oxygen binding to the diferrous site.


    Organizational Affiliation

    Department of Biochemistry and Biophysics, Stockholm University, S-10691 Stockholm, Sweden.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Ribonucleoside-diphosphate reductase 1 beta chain
A, B
375Escherichia coli (strain K12)Mutation(s): 2 
Gene Names: nrdB (ftsB)
EC: 1.17.4.1
Find proteins for P69924 (Escherichia coli (strain K12))
Go to UniProtKB:  P69924
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
AZI
Query on AZI

Download SDF File 
Download CCD File 
A
AZIDE ION
N3
IVRMZWNICZWHMI-UHFFFAOYSA-N
 Ligand Interaction
FE
Query on FE

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Download CCD File 
A, B
FE (III) ION
Fe
VTLYFUHAOXGGBS-UHFFFAOYSA-N
 Ligand Interaction
HG
Query on HG

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Download CCD File 
A, B
MERCURY (II) ION
Hg
BQPIGGFYSBELGY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.182 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 73.893α = 90.00
b = 84.501β = 90.00
c = 113.963γ = 90.00
Software Package:
Software NamePurpose
TNTphasing
DENZOdata reduction
SCALEPACKdata scaling
TNTrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-12-23
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance