Crystal Structure of Aluminum-Bound Ovotransferrin at 2.15 Angstrom Resolution

Experimental Data Snapshot

  • Resolution: 2.15 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.206 

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Structure of aluminium-bound ovotransferrin at 2.15 Angstroms resolution.

Mizutani, K.Mikami, B.Aibara, S.Hirose, M.

(2005) Acta Crystallogr D Biol Crystallogr 61: 1636-1642

  • DOI: https://doi.org/10.1107/S090744490503266X
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Transferrin, well known as an iron-transport protein, can bind other metal ions, including toxic ones, and is considered to play an important role in the transportation of such metal ions. Here, a crystal structure of aluminium-bound transferrin is described for the first time. Colourless needle-shaped crystals of aluminium-bound ovotransferrin were obtained in PEG 400 solution. Structural determination was performed by molecular replacement using diferric (iron-bound) ovotransferrin as a model and the structural refinement was performed in the 50-2.15 Angstroms resolution range. The overall organization of the aluminium-bound form is almost the same as the iron-bound form: the protein is folded into two homologous lobes (N- and C-lobes) with two domains; two metal-binding sites are located within the inter-domain clefts of each lobe. Four residues (one Asp, two Tyr and one His) and one bicarbonate anion were found to bind an aluminium ion in either lobe, as in the iron-bound form. The highly similar domain-closed structure of the Al(3+)-bound form may permit the binding of Al(3+)-bound transferrin to the transferrin receptor. An unusual interaction, the dilysine trigger, which facilitates iron release at low pH in the endosome, was also found in the Al(3+)-bound form. These findings support the participation of transferrin in the transport of Al(3+) ions in vivo.

  • Organizational Affiliation

    Laboratory of Applied Structural Biology, Division of Applied Life Sciences, The Graduate School of Agriculture, Kyoto University, Uji, Japan. kmizuatani@kais-kyoto-u.ac.jp

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Ovotransferrin686Gallus gallusMutation(s): 0 
Find proteins for P02789 (Gallus gallus)
Explore P02789 
Go to UniProtKB:  P02789
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP02789
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.15 Å
  • R-Value Free: 0.243 
  • R-Value Work: 0.206 
  • R-Value Observed: 0.206 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 72.353α = 90
b = 59.184β = 95.72
c = 87.974γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-11-29
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-10-25
    Changes: Data collection, Database references, Derived calculations, Refinement description