Crystal Structure of Struthiocalcin-1, a different crystal form.

Experimental Data Snapshot

  • Resolution: 1.50 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.188 
  • R-Value Observed: 0.189 

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Crystal Structure of Struthiocalcin-1, an Intramineral Protein from Struthio Camelus Eggshell, in Two Different Crystal Forms.

Ruiz-Arellano, R.R.Medrano, F.J.Moreno, A.Romero, A.

(2015) Acta Crystallogr D Biol Crystallogr 71: 809

  • DOI: https://doi.org/10.1107/S139900471500125X
  • Primary Citation of Related Structures:  
    4UWW, 4UXM

  • PubMed Abstract: 

    Biomineralization is the process by which living organisms produce minerals. One remarkable example is the formation of eggshells in birds. Struthiocalcins present in the ostrich (Struthio camellus) eggshell matrix act as biosensors of calcite growth during eggshell formation. Here, the crystal structure of struthiocalcin-1 (SCA-1) is reported in two different crystal forms. The structure is a compact single domain with an α/β fold characteristic of the C-type lectin family. In contrast to the related avian ovocleidin OC17, the electrostatic potential on the molecular surface is dominated by an acidic patch. Scanning electron microscopy combined with Raman spectroscopy indicates that these intramineral proteins (SCA-1 and SCA-2) induce calcium carbonate precipitation, leading to the formation of a stable form of calcite in the mature eggshell. Finally, the implications of these two intramineral proteins SCA-1 and SCA-2 in the nucleation of calcite during the formation of eggshells in ratite birds are discussed.

  • Organizational Affiliation

    Biología Físico-Química, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
STRUTHIOCALCIN-1132Struthio camelusMutation(s): 0 
Find proteins for P83514 (Struthio camelus)
Explore P83514 
Go to UniProtKB:  P83514
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP83514
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on BE7

Download Ideal Coordinates CCD File 
C7 H5 Cl Hg O2
Experimental Data & Validation

Experimental Data

  • Resolution: 1.50 Å
  • R-Value Free: 0.213 
  • R-Value Work: 0.188 
  • R-Value Observed: 0.189 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 32.67α = 90
b = 55.91β = 90
c = 72.06γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALEdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-04-08
    Type: Initial release
  • Version 1.1: 2015-04-22
    Changes: Database references
  • Version 1.2: 2018-04-04
    Changes: Data collection