The structure of bovine beta-lactoglobulin in novel crystals grown at pH 3.8

Experimental Data Snapshot

  • Resolution: 2.30 Å
  • R-Value Free: 0.261 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.210 

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The structure of bovine beta-lactoglobulin in crystals grown at pH 3.8 exhibiting novel threefold twinning.

Yeates, T.O.McPherson, A.

(2019) Acta Crystallogr F Struct Biol Commun 75: 640-645

  • DOI: https://doi.org/10.1107/S2053230X1901224X
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Bovine β-lactoglobulin was crystallized from 3 M NaCl buffered at pH 3.8 with sodium citrate as thick hexagonal prisms of greater than 1 mm in edge length. Analyses of the X-ray diffraction intensities using three different current algorithms were unanimous in specifying the space group to be P6 3 22, with unit-cell dimensions a = b = 75.47, c = 140.79 Å. No progress could be made, however, towards an acceptable solution by molecular replacement using this symmetry. In the end, it was found that the true space group was C222 1 , a subgroup of P6 3 22, with a = 65.89, b = 114.12, c = 140.51 Å, with the apparent 622 symmetry arising from an unusual threefold or tritohedral twinning. An assembly based on a model of the protein in another crystal form (PDB entry 1beb) containing three molecules in the asymmetric unit was refined to 2.3 Å resolution with a final R factor of 0.23 and R free of 0.26. NCS restraints were maintained throughout. For the most part, the molecules found in this crystal form are virtually the same as in PDB entry 1beb, although there are numerous local variations, particularly in loop elements, rotamer conformation differences and some alterations, including additions, at the termini.

  • Organizational Affiliation

    Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Beta-lactoglobulin178Bos taurusMutation(s): 0 
Find proteins for P02754 (Bos taurus)
Explore P02754 
Go to UniProtKB:  P02754
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP02754
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
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Experimental Data & Validation

Experimental Data

Unit Cell:
Length ( Å )Angle ( ˚ )
a = 65.888α = 90
b = 114.121β = 90
c = 140.506γ = 90
Software Package:
Software NamePurpose
XDSdata reduction
Aimlessdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-01-23
    Type: Initial release
  • Version 1.1: 2019-11-06
    Changes: Data collection, Database references
  • Version 1.2: 2023-10-11
    Changes: Data collection, Database references, Refinement description