Experimental Data Snapshot

  • Resolution: 1.15 Å
  • R-Value Free: 0.188 
  • R-Value Work: 0.150 
  • R-Value Observed: 0.150 

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This is version 1.3 of the entry. See complete history


The C1 subunit of alpha-crustacyanin: the de novo phasing of the crystal structure of a 40 kDa homodimeric protein using the anomalous scattering from S atoms combined with direct methods.

Gordon, E.J.Leonard, G.A.McSweeney, S.Zagalsky, P.F.

(2001) Acta Crystallogr D Biol Crystallogr 57: 1230-1237

  • DOI: https://doi.org/10.1107/s0907444901009362
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The previously unknown crystal structure of the C(1) subunit of the carotenoid-binding protein alpha-crustacyanin has been determined using the anomalous scattering available at 1.77 A wavelength to determine the partial structure of the S atoms intrinsic to the native protein. The resulting 'heavy-atom' phases, in conjunction with near-atomic resolution (d(min) = 1.15 A) data, were then used to initiate successful structure determination using a direct-methods approach. This is, to the authors' knowledge, the first time such a small anomalous signal ( approximately 1%) has been used to aid the determination of a macromolecular structure. As well as the structure itself, the methods used during data collection and those used in the elucidation of the sulfur 'heavy-atom' partial structure are described here. As predicted, the C(1) subunit adopts a tertiary structure typical of the lipocalin superfamily: an eight-stranded antiparallel beta-barrel with a repeated +1 topology. The beta-barrel has a calyx shape with the two molecules in the asymmetric unit interacting in such a way that the open ends of each calyx face each other, although they do not form a single elongated pocket. A comparison of this structure with those of other members of the lipocalin superfamily has allowed speculation as to the nature of carotenoid binding by the protein.

  • Organizational Affiliation

    Macromolecular Crystallography, European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble CEDEX, France. gordon@esrf.fr

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
181N/AMutation(s): 0 
Find proteins for P80029 (Homarus gammarus)
Explore P80029 
Go to UniProtKB:  P80029
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP80029
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.15 Å
  • R-Value Free: 0.188 
  • R-Value Work: 0.150 
  • R-Value Observed: 0.150 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 41.23α = 90
b = 79.72β = 90
c = 109.49γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-09-19
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-10-04
    Changes: Refinement description