2C32

Co-axial association of recombinant eye lens aquaporin-0 observed in loosely packed 3D-crystals


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 7.01 Å
  • R-Value Free: 0.387 
  • R-Value Work: 0.390 
  • R-Value Observed: 0.390 

Starting Model: experimental
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This is version 1.3 of the entry. See complete history


Literature

Co-Axial Association of Recombinant Eye Lens Aquaporin-0 Observed in Loosely Packed 3D-Crystals

Palanivelu, D.V.Kozono, D.E.Engel, A.Suda, K.Lustig, A.Agre, P.Schirmer, T.

(2006) J Mol Biol 355: 605

  • DOI: https://doi.org/10.1016/j.jmb.2005.10.032
  • Primary Citation of Related Structures:  
    2C32

  • PubMed Abstract: 

    Aquaporin-0 (AQP0) is the major membrane protein in vertebrate eye lenses. It has been proposed that AQP0 tetramers mediate contact between membranes of adjacent lens fiber cells, which would be consistent with the extraordinarily narrow inter-cellular spacing. We have obtained 3D crystals of recombinant bovine AQP0 that diffract to 7.0 A resolution. The crystal packing was determined by molecular replacement and shows that, within the cubic lattice, AQP0 tetramers are associated head-to-head along their 4-fold axes. Oligomeric states larger than the tetramer were also observed in solution by native gel electrophoresis and analytical ultracentrifugation methods. In the crystals, there are no direct contacts between octamers, and it can thus be inferred that crystalline order is mediated solely by the detergent belts surrounding the membrane protein. Across the tetramer-tetramer interface, extracellular loops A and C interdigitate at the center and the perimeter of the octamer, respectively. The octamer structure is compared with that of the recently determined structure of truncated ovine AQP0 derived from electron diffraction of 2D crystals. Intriguingly, also in these crystals, octamers are observed, but with significantly different relative tetramer-tetramer orientations. The interactions observed in the loosely packed 3D crystals reported here may in fact represent an in vivo association mode between AQP0 tetramers from juxtaposed membranes in the eye lens.


  • Organizational Affiliation

    Division of Structural Biology, Biozentrum, University of Basel, Klingelbergstr. 70, CH-4056 Basel, Switzerland.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
LENS FIBER MAJOR INTRINSIC PROTEIN263Bos taurusMutation(s): 0 
Membrane Entity: Yes 
UniProt
Find proteins for P06624 (Bos taurus)
Explore P06624 
Go to UniProtKB:  P06624
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP06624
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 7.01 Å
  • R-Value Free: 0.387 
  • R-Value Work: 0.390 
  • R-Value Observed: 0.390 
  • Space Group: I 4 3 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 188.271α = 90
b = 188.271β = 90
c = 188.271γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-12-07
    Type: Initial release
  • Version 1.1: 2011-05-07
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-12-13
    Changes: Data collection, Database references, Other, Refinement description