1YFD

Crystal structure of the Y122H mutant of ribonucleotide reductase R2 protein from E. coli


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.173 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

A new tyrosyl radical on Phe208 as ligand to the diiron center in Escherichia coli ribonucleotide reductase, mutant R2-Y122H. Combined x-ray diffraction and EPR/ENDOR studies

Kolberg, M.Logan, D.T.Bleifuss, G.Poetsch, S.Sjoeberg, B.M.Graeslund, A.Lubitz, W.Lassmann, G.Lendzian, F.

(2005) J.Biol.Chem. 280: 11233-11246

  • DOI: 10.1074/jbc.M414634200

  • PubMed Abstract: 
  • The R2 protein subunit of class I ribonucleotide reductase (RNR) belongs to a structurally related family of oxygen bridged diiron proteins. In wild-type R2 of Escherichia coli, reductive cleavage of molecular oxygen by the diferrous iron center gene ...

    The R2 protein subunit of class I ribonucleotide reductase (RNR) belongs to a structurally related family of oxygen bridged diiron proteins. In wild-type R2 of Escherichia coli, reductive cleavage of molecular oxygen by the diferrous iron center generates a radical on a nearby tyrosine residue (Tyr122), which is essential for the enzymatic activity of RNR, converting ribonucleotides into deoxyribonucleotides. In this work, we characterize the mutant E. coli protein R2-Y122H, where the radical site is substituted with a histidine residue. The x-ray structure verifies the mutation. R2-Y122H contains a novel stable paramagnetic center which we name H, and which we have previously proposed to be a diferric iron center with a strongly coupled radical, Fe(III)Fe(III)R.. Here we report a detailed characterization of center H, using 1H/2H -14N/15N- and 57Fe-ENDOR in comparison with the Fe(III)Fe(IV) intermediate X observed in the iron reconstitution reaction of R2. Specific deuterium labeling of phenylalanine residues reveals that the radical results from a phenylalanine. As Phe208 is the only phenylalanine in the ligand sphere of the iron site, and generation of a phenyl radical requires a very high oxidation potential, we propose that in Y122H residue Phe208 is hydroxylated, as observed earlier in another mutant (R2-Y122F/E238A), and further oxidized to a phenoxyl radical, which is coordinated to Fe1. This work demonstrates that small structural changes can redirect the reactivity of the diiron site, leading to oxygenation of a hydrocarbon, as observed in the structurally similar methane monoxygenase, and beyond, to formation of a stable iron-coordinated radical.


    Organizational Affiliation

    Max-Volmer-Laboratory, Institute for Chemistry, PC 14, Technical University Berlin, D-10623 Berlin, Germany.




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): 1 
Gene Names: nrdB (ftsB)
EC: 1.17.4.1
Find proteins for P69924 (Escherichia coli (strain K12))
Go to UniProtKB:  P69924
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FEO
Query on FEO

Download SDF File 
Download CCD File 
A, B
MU-OXO-DIIRON
Fe2 O
NPMYUMBHPJGBFA-UHFFFAOYSA-N
 Ligand Interaction
HG
Query on HG

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

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.173 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 74.040α = 90.00
b = 84.740β = 90.00
c = 115.030γ = 90.00
Software Package:
Software NamePurpose
XFITdata reduction
XDSdata scaling
REFMACrefinement
MAR345data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-02-15
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-10-11
    Type: Refinement description