Biological Assembly 1  

 3D View: Structure | 1D-3D View | Validation Report

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 11.96 kDa 
• Atom Count: 842 
• Modelled Residue Count: 109 
• Deposited Residue Count: 109 
• Unique protein chains: 1

2K7M

Structure of the Connexin40 Carboxyl terminal Domain

• PDB DOI: 10.2210/pdb2K7M/pdb

• Classification: MEMBRANE PROTEIN
• Organism(s): Rattus norvegicus
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2008-08-14 Released: 2009-07-28 
• Deposition Author(s): Bouvier, D., Spagnol, G., Kieken, F., Vitrac, H., Kellezi, A., Forge, V.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 10 
• Selection Criteria: structures with the lowest energy 

Literature

Characterization of the structure and intermolecular interactions between the connexin40 and connexin43 carboxyl-terminal and cytoplasmic loop domains.

Bouvier, D., Spagnol, G., Chenavas, S., Kieken, F., Vitrac, H., Brownell, S., Kellezi, A., Forge, V., Sorgen, P.L.

(2009) J Biol Chem 284: 34257-34271

• PubMed: 19808665 
• DOI: 10.1074/jbc.M109.039594
• Primary Citation of Related Structures:  
  2K7M


• PubMed Abstract: 
  

Gap junctions are intercellular channels that allow the passage of ions, small molecules, and second messengers that are essential for the coordination of cellular function. They are formed by two hemichannels, each constituted by the oligomerization of six connexins (Cx). Among the 21 different human Cx isoforms, studies have suggested that in the heart, Cx40 and Cx43 can oligomerize to form heteromeric hemichannels. The mechanism of heteromeric channel regulation has not been clearly defined. Tissue ischemia leads to intracellular acidification and closure of Cx43 and Cx40 homomeric channels. However, coexpression of Cx40 and Cx43 in Xenopus oocytes enhances the pH sensitivity of the channel. This phenomenon requires the carboxyl-terminal (CT) part of both connexins. In this study we used different biophysical methods to determine the structure of the Cx40CT and characterize the Cx40CT/Cx43CT interaction. Our results revealed that the Cx40CT is an intrinsically disordered protein similar to the Cx43CT and that the Cx40CT and Cx43CT can interact. Additionally, we have identified an interaction between the Cx40CT and the cytoplasmic loop of Cx40 as well as between the Cx40CT and the cytoplasmic loop of Cx43 (and vice versa). Our studies support the "particle-receptor" model for pH gating of Cx40 and Cx43 gap junction channels and suggest that interactions between cytoplasmic regulatory domains (both homo- and hetero-connexin) could be important for the regulation of heteromeric channels.

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Organizational Affiliation: 

Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Gap junction alpha-5 protein	A	109	Rattus norvegicus	Mutation(s): 0  Gene Names: Gja5, Cxn-40
UniProt
Find proteins for P28234 (Rattus norvegicus) Explore P28234  Go to UniProtKB:  P28234

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 10 
• Selection Criteria: structures with the lowest energy 
• OLDERADO: 2K7M Olderado

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2008-08-14 
• Released Date: 2009-07-28 
Deposition Author(s): Bouvier, D., Spagnol, G., Kieken, F., Vitrac, H., Kellezi, A., Forge, V.

Revision History  

• Version 1.0: 2009-07-28
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Version format compliance
• Version 1.2: 2022-03-16
  Changes: Data collection, Database references, Derived calculations