5ERA

Human Connexin-26 (Calcium-free)

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.80 Å
  • R-Value Free: 0.333 
  • R-Value Work: 0.300 
  • R-Value Observed: 0.304 

wwPDB Validation   3D Report Full Report



Literature

An electrostatic mechanism for Ca(2+)-mediated regulation of gap junction channels.

Bennett, B.C., Purdy, M.D., Baker, K.A., Acharya, C., McIntire, W.E., Stevens, R.C., Zhang, Q., Harris, A.L., Abagyan, R., Yeager, M.

(2016) Nat Commun 7: 8770-8770

  • DOI: 10.1038/ncomms9770
  • Primary Citation of Related Structures:  
    5ERA, 5ER7

  • PubMed Abstract: 

    • Gap junction channels mediate intercellular signalling that is crucial in tissue development, homeostasis and pathologic states such as cardiac arrhythmias, cancer and trauma. To explore the mechanism by which Ca(2+) blocks intercellular communication du ...

    Gap junction channels mediate intercellular signalling that is crucial in tissue development, homeostasis and pathologic states such as cardiac arrhythmias, cancer and trauma. To explore the mechanism by which Ca(2+) blocks intercellular communication during tissue injury, we determined the X-ray crystal structures of the human Cx26 gap junction channel with and without bound Ca(2+). The two structures were nearly identical, ruling out both a large-scale structural change and a local steric constriction of the pore. Ca(2+) coordination sites reside at the interfaces between adjacent subunits, near the entrance to the extracellular gap, where local, side chain conformational rearrangements enable Ca(2+)chelation. Computational analysis revealed that Ca(2+)-binding generates a positive electrostatic barrier that substantially inhibits permeation of cations such as K(+) into the pore. Our results provide structural evidence for a unique mechanism of channel regulation: ionic conduction block via an electrostatic barrier rather than steric occlusion of the channel pore.

    Related Citations: 
    • Steroid-based facial amphiphiles for stabilization and crystallization of membrane proteins.
      Lee, S.C., Bennett, B.C., Hong, W.X., Fu, Y., Baker, K.A., Marcoux, J., Robinson, C.V., Ward, A.B., Halpert, J.R., Stevens, R.C., Stout, C.D., Yeager, M.J., Zhang, Q.
      (2013) Proc Natl Acad Sci U S A 110: E1203
    Organizational Affiliation: 

    Department of Medicine, Division of Cardiovascular Medicine, University of Virginia School of Medicine, Charlottesville, Virginia 22908, USA.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Gap junction beta-2 protein A, B226Homo sapiensMutation(s): 3 
Gene Names: GJB2
Find proteins for P29033 (Homo sapiens)
Explore P29033 
Go to UniProtKB:  P29033
NIH Common Fund Data Resources
PHAROS:  P29033
GTEx:  ENSG00000165474
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.80 Å
  • R-Value Free: 0.333 
  • R-Value Work: 0.300 
  • R-Value Observed: 0.304 
  • Space Group: H 3 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 155.727α = 90
b = 155.727β = 90
c = 160.699γ = 120
Software Package:
Software NamePurpose
SCALEPACKdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
HKL-2000data reduction
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2016-01-27
    Type: Initial release