The 2.6 A Structure Resolution of Rhodobacter capsulatus Bacterioferritin with Metal-free Dinuclear Site and Heme Iron in a Crystallographic Special Position

Experimental Data Snapshot

  • Resolution: 2.60 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.225 

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The 2.6 A resolution structure of Rhodobacter capsulatus bacterioferritin with metal-free dinuclear site and heme iron in a crystallographic 'special position'.

Cobessi, D.Huang, L.S.Ban, M.Pon, N.G.Daldal, F.Berry, E.A.

(2002) Acta Crystallogr D Biol Crystallogr 58: 29-38

  • DOI: https://doi.org/10.1107/s0907444901017267
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Bacterioferritin from Rhodobacter capsulatus was crystallized and its structure was solved at 2.6 A resolution. This first structure of a bacterioferritin from a photosynthetic organism is a spherical particle of 24 subunits displaying 432 point-group symmetry like ferritin and bacterioferritin from Escherichia coli. Crystallized in the I422 space group, its structural analysis reveals for the first time the non-symmetric heme molecule located on a twofold crystallographic symmetry axis. Other hemes of the protomer are situated on twofold noncrystallographic axes. Apparently, both types of sites bind heme in two orientations, leading to an average structure consisting of a symmetric 50:50 mixture, thus satisfying the crystallographic and noncrystallographic symmetry of the crystal. Five water molecules are situated close to the heme, which is bound in a hydrophobic pocket and axially coordinated by two crystallographic or noncrystallographically related methionine residues. Its ferroxidase center, in which Fe(II) is oxidized to Fe(III), is empty or fractionally occupied by a metal ion. Two positions are observed for the coordinating Glu18 side chain instead of one in the E. coli enzyme in which the site is occupied. This result suggests that the orientation of the Glu18 side chain could be constrained by this interaction.

  • Organizational Affiliation

    Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley CA 94720, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B, C
161Rhodobacter capsulatusMutation(s): 0 
Find proteins for Q59738 (Rhodobacter capsulatus)
Explore Q59738 
Go to UniProtKB:  Q59738
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ59738
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.60 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.225 
  • Space Group: I 4 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 142.37α = 90
b = 142.37β = 90
c = 140.88γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2002-01-09
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance