3E1Q

Crystal structure of W133F variant E. coli Bacterioferritn with iron.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.263 
  • R-Value Work: 0.245 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Monitoring the iron status of the ferroxidase center of Escherichia coli bacterioferritin using fluorescence spectroscopy.

Lawson, T.L.Crow, A.Lewin, A.Yasmin, S.Moore, G.R.Le Brun, N.E.

(2009) Biochemistry 48: 9031-9039

  • DOI: 10.1021/bi900869x
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Ferritins solubilize and detoxify the essential metal iron through formation of a ferric mineral within the protein's central cavity. Key to this activity is an intrasubunit catalytic dinuclear iron center called the ferroxidase center. Here we show ...

    Ferritins solubilize and detoxify the essential metal iron through formation of a ferric mineral within the protein's central cavity. Key to this activity is an intrasubunit catalytic dinuclear iron center called the ferroxidase center. Here we show that the fluorescence intensity of Escherichia coli bacterioferritin (BFR), due to the presence of two tryptophan residues (Trp35 and Trp133) in each of the 24 subunits, is highly sensitive to the iron status of the ferroxidase center and is quenched to different extents by Fe2+ and Fe3+. Recovery of the quench following oxidation of Fe2+ to Fe3+ at the ferroxidase center was not observed, indicating that the di-Fe3+ form of the center is stable. Studies of the single-tryptophan variants W35F and W133F showed that Trp133, which lies approximately 10 A from the ferroxidase center, is primarily responsible for the observed fluorescence sensitivity to iron, while studies of a stable E. coli BFR subunit dimer demonstrated that the observed quench properties are principally derived from the interaction of iron with tryptophan residues within the subunit dimer. A double-tryptophan variant (W35F/W133F) was found to exhibit fluorescence from the seven tyrosine residues present in each subunit, which was also sensitive to the iron status of the ferroxidase center. Finally, we demonstrate using Zn2+, a potent competitive inhibitor of Fe2+ binding and oxidation, that the fluorescence response can be used to monitor the loss of iron from the ferroxidase center.


    Organizational Affiliation

    Centre for Molecular and Structural Biochemistry, School of Chemistry, University of East Anglia, Norwich NR4 7TJ, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
BACTERIOFERRITIN
A, B, C, D, E, F, G, H, I, J, K, L
158Escherichia coli (strain K12)Mutation(s): 1 
Gene Names: bfr
EC: 1.16.3.1
Find proteins for P0ABD3 (Escherichia coli (strain K12))
Go to UniProtKB:  P0ABD3
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B, C, D, E, F, G, H, I, J, K, L
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
HEM
Query on HEM

Download SDF File 
Download CCD File 
A, D, F, G, I, L
PROTOPORPHYRIN IX CONTAINING FE
HEME
C34 H32 Fe N4 O4
KABFMIBPWCXCRK-RGGAHWMASA-L
 Ligand Interaction
FE2
Query on FE2

Download SDF File 
Download CCD File 
A, B, C, D, E, F, G, H, I, J, K, L
FE (II) ION
Fe
CWYNVVGOOAEACU-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.6 Å
  • R-Value Free: 0.263 
  • R-Value Work: 0.245 
  • Space Group: P 42 21 2
Unit Cell:
Length (Å)Angle (°)
a = 207.659α = 90.00
b = 207.659β = 90.00
c = 142.767γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling
MOLREPphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-08-18
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance