1WPA

1.5 Angstrom crystal structure of human occludin fragment 413-522


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.237 
  • R-Value Observed: 0.240 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structure of the conserved cytoplasmic C-terminal domain of occludin: identification of the ZO-1 binding surface.

Li, Y.Fanning, A.S.Anderson, J.M.Lavie, A.

(2005) J Mol Biol 352: 151-164

  • DOI: 10.1016/j.jmb.2005.07.017
  • Primary Citation of Related Structures:  
    1XAW, 1WPA

  • PubMed Abstract: 
  • Occludin is a transmembrane protein localized at tight junctions whose functions are complex yet poorly understood. Current evidence supports a role for occludin in both the formation of the paracellular barrier and in cell signaling. While the N-ter ...

    Occludin is a transmembrane protein localized at tight junctions whose functions are complex yet poorly understood. Current evidence supports a role for occludin in both the formation of the paracellular barrier and in cell signaling. While the N-terminal extracellular domains of occludin mediate homotypic adhesion, the distal C-terminal cytoplasmic domain of occludin controls protein targeting and endocytosis. The C terminus can also bind to the scaffolding proteins ZO-1, ZO-2, ZO-3, cingulin, the membrane trafficking protein VAP33, and the cytoskeletal protein F-actin, suggesting an important role for this domain. This domain is highly homologous to an important functional domain in the C terminus of the ELL family of RNA polymerase II transcription factors. To explore the function of occludin, we determined the high-resolution crystal structure of its C-terminal distal cytoplasmic domain. The structure comprises three helices that form two separate anti-parallel coiled-coils and a loop that packs tightly against one of the coiled-coils. Using in vitro binding studies and site-directed mutagenesis, we have identified a large positively charged surface that contains the binding site for ZO-1, and this surface is required for proper localization of occludin to cell-cell junctions. On the basis of sequence conservation, we predict that occludin domains from different species and the C-terminal domain of the ELL transcription factors share a very similar structure. Our results provide a model to further test the function of occludin and its binding to other proteins.


    Organizational Affiliation

    Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL 60607, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
OccludinA114Homo sapiensMutation(s): 0 
Gene Names: OCLN
Find proteins for Q16625 (Homo sapiens)
Explore Q16625 
Go to UniProtKB:  Q16625
NIH Common Fund Data Resources
PHAROS  Q16625
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.237 
  • R-Value Observed: 0.240 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 33.02α = 90
b = 35.31β = 90
c = 107.82γ = 90
Software Package:
Software NamePurpose
CNSrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-09-06
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2014-09-17
    Changes: Database references