Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 56.94 kDa 
• Atom Count: 3056 
• Modelled Residue Count: 368 
• Deposited Residue Count: 460 
• Unique protein chains: 1

7QEO

human Connexin 26 at 55mm Hg PCO2, pH7.4: two masked subunits, class C

• PDB DOI: 10.2210/pdb7QEO/pdb
• EM Map EMD-13935: EMDB EMDataResource

• Classification: MEMBRANE PROTEIN
• Organism(s): Homo sapiens
• Expression System: Spodoptera frugiperda
• Mutation(s): No 


• Deposited: 2021-12-03 Released: 2022-06-22 
• Deposition Author(s): Brotherton, D.H., Cameron, A.D., Savva, C.G., Ragan, T.J.
• Funding Organization(s): Medical Research Council (MRC, United Kingdom), Leverhulme Trust

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 2.90 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Conformational changes and CO 2 -induced channel gating in connexin26.

Brotherton, D.H., Savva, C.G., Ragan, T.J., Dale, N., Cameron, A.D.

(2022) Structure 30: 697-706.e4

• PubMed: 35276081 
• DOI: 10.1016/j.str.2022.02.010
• Primary Citation of Related Structures:  
  7QEO, 7QEQ, 7QER, 7QES, 7QET, 7QEU, 7QEV, 7QEW


• PubMed Abstract: 
  

Connexins form large-pore channels that function either as dodecameric gap junctions or hexameric hemichannels to allow the regulated movement of small molecules and ions across cell membranes. Opening or closing of the channels is controlled by a variety of stimuli, and dysregulation leads to multiple diseases. An increase in the partial pressure of carbon dioxide (PCO ₂ ) has been shown to cause connexin26 (Cx26) gap junctions to close. Here, we use cryoelectron microscopy (cryo-EM) to determine the structure of human Cx26 gap junctions under increasing levels of PCO ₂ . We show a correlation between the level of PCO ₂ and the size of the aperture of the pore, governed by the N-terminal helices that line the pore. This indicates that CO ₂ alone is sufficient to cause conformational changes in the protein. Analysis of the conformational states shows that movements at the N terminus are linked to both subunit rotation and flexing of the transmembrane helices.

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Organizational Affiliation: 

School of Life Sciences, University of Warwick, Gibbet Hill Road, CV4 7AL Coventry, UK. Electronic address: [e-mail].

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Gap junction beta-2 protein	A, B	230	Homo sapiens	Mutation(s): 0  Gene Names: GJB2
UniProt & NIH Common Fund Data Resources
Find proteins for P29033 (Homo sapiens) Explore P29033  Go to UniProtKB:  P29033
PHAROS:  P29033

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
PTY	E [auth A], H [auth B]	PHOSPHATIDYLETHANOLAMINE C40 H80 N O8 P NJGIRBISCGPRPF-KXQOOQHDSA-N
LMT	C [auth A], D [auth A], F [auth B], G [auth B]	DODECYL-BETA-D-MALTOSIDE C24 H46 O11 NLEBIOOXCVAHBD-QKMCSOCLSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 2.90 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Structure Validation

Entry History & Funding Information

Deposition Data

• Deposited Date: 2021-12-03 
• Released Date: 2022-06-22 
Deposition Author(s): Brotherton, D.H., Cameron, A.D., Savva, C.G., Ragan, T.J.

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Funding Organization	Location	Grant Number
Medical Research Council (MRC, United Kingdom)	United Kingdom	MR/P010393/1
Leverhulme Trust	United Kingdom	RPG-2015-090

Revision History  

• Version 1.0: 2022-06-22
  Type: Initial release