2AKQ

The structure of bovine B-lactoglobulin A in crystals grown at very low ionic strength


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.224 
  • R-Value Observed: 0.214 

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This is version 1.2 of the entry. See complete history


Literature

Structure of bovine beta-lactoglobulin (variant A) at very low ionic strength

Adams, J.J.Anderson, B.F.Norris, G.E.Creamer, L.K.Jameson, G.B.

(2006) J Struct Biol 154: 246-254

  • DOI: 10.1016/j.jsb.2005.12.010
  • Primary Citation of Related Structures:  
    2AKQ

  • PubMed Abstract: 
  • Bovine beta-lactoglobulin (BLG) is a globular protein of uncertain physiological function and a member of the lipocalin superfamily of proteins. Here, we present the X-ray structure at 3.0 angstroms of BLG (variant A) from an orthorhombic (P2(1)2(1)2(1)) pseudo-tetragonal crystal form that suffers from pseudo-merohedral twinning (final R(working) = 0 ...

    Bovine beta-lactoglobulin (BLG) is a globular protein of uncertain physiological function and a member of the lipocalin superfamily of proteins. Here, we present the X-ray structure at 3.0 angstroms of BLG (variant A) from an orthorhombic (P2(1)2(1)2(1)) pseudo-tetragonal crystal form that suffers from pseudo-merohedral twinning (final R(working) = 0.224, R(free) = 0.265). Crystals were grown by dialysis against ultra-purified water (i.e., at very low ionic strength), at pH approximately 5.2 (approximately pI), conditions vastly different from all other BLG structures determined previously. This allows critical assessment of the BLG structure and of the influence that pH, ionic strength, and crystal packing may have on the molecular structure of BLG. The pH-sensitive EF loop is found in the closed conformation characteristic of BLG at pH less than 7 and moderate to high ionic strength. Although the hydrophobic pocket appears to be empty, the presence of highly disordered water molecules cannot be excluded. The dimer interface and the hydrophobic pocket (calyx) are preserved. However, the orientation of the subunits in the dimer varies considerably with crystal form. Structure is deposited with PDB ID 2akq.


    Related Citations: 
    • Bovine beta-lactoglobulin at 1.8 A resolution--still an enigmatic lipocalin
      Brownlow, S., Morais-Cabral, J.H., Cooper, R., Flower, D.R., Yewdall, S.J., Polikarpov, I., North, A.C., Sawyer, L.
      (1997) Structure 5: 481
    • Structural basis of the Tanford transition of bovine beta-lactoglobulin
      Qin, B.Y., Bewley, M.C., Creamer, L.K., Baker, H.M., Baker, E.N., Jameson, G.B.
      (1998) Biochemistry 37: 14014
    • 12-Bromododecanoic acid binds inside the calyx of bovine beta-lactoglobulin
      Qin, B.Y., Creamer, L.K., Baker, E.N., Jameson, G.B.
      (1998) FEBS Lett 438: 272

    Organizational Affiliation

    Centre for Structural Biology, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Beta-lactoglobulin variant AA, B, C, D162Bos taurusMutation(s): 0 
Gene Names: LGB
UniProt
Find proteins for P02754 (Bos taurus)
Explore P02754 
Go to UniProtKB:  P02754
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.00 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.224 
  • R-Value Observed: 0.214 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 68.191α = 90
b = 68.231β = 90
c = 131.455γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing
SHELXL-97refinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-08-16
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance