5KJG

Connexin 26 G12R mutant NMR structure

  • Classification: TRANSPORT PROTEIN
  • Organism(s): Homo sapiens
  • Mutation(s): 

  • Deposited: 2016-06-19 Released: 2016-09-28 
  • Deposition Author(s): Dowd, T.L., Bargiello, T.A.
  • Funding Organization(s): National Institutes of Health/National Institute of General Medical Sciences 

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Submitted: 20 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural studies of N-terminal mutants of Connexin 26 and Connexin 32 using (1)H NMR spectroscopy.

Batir, Y.Bargiello, T.A.Dowd, T.L.

(2016) Arch.Biochem.Biophys. 608: 8-19

  • DOI: 10.1016/j.abb.2016.06.019
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Alterations in gap junctions underlie the etiologies of syndromic deafness (KID) and Charcot-Marie Tooth disease (CMTX). Functional gap junctions are composed of connexin molecules with N-termini containing a flexible turn around G12, inserting the N ...

    Alterations in gap junctions underlie the etiologies of syndromic deafness (KID) and Charcot-Marie Tooth disease (CMTX). Functional gap junctions are composed of connexin molecules with N-termini containing a flexible turn around G12, inserting the N-termini into the channel pore allowing voltage gating. The loss of this turn correlates with loss of Connexin 32 (Cx32) function by impaired trafficking to the cell membrane. Using (1)H NMR we show the N-terminus of a syndromic deafness mutation Cx26G12R, producing "leaky channels", contains a turn around G12 which is less structured and more flexible than wild-type. In contrast, the N-terminal structure of the same mutation in Cx32 chimera, Cx32*43E1G12R shows a larger constricted turn and no membrane current expression but forms membrane inserted hemichannels. Their function was rescued by formation of heteromeric channels with wild type subunits. We suggest the inflexible Cx32G12R N-terminus blocks ion conduction in homomeric channels and this channel block is relieved by incorporation of wild type subunits. In contrast, the increased open probability of Cx26G12R hemichannels is likely due to the addition of positive charge in the channel pore changing pore electrostatics and impairing hemichannel regulation by Ca(2+). These results provide mechanistic information on aberrant channel activity observed in disease.


    Organizational Affiliation

    Department of Chemistry, Brooklyn College, Brooklyn, NY 11210, United States; Ph.D. Program in Chemistry and Biochemistry, The Graduate Center of the City University of New York, New York, NY, 10016, United States. Electronic address: TDowd@brooklyn.cuny.edu.,Department of Chemistry, Brooklyn College, Brooklyn, NY 11210, United States.,Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, United States.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Gap junction beta-2 protein
A
23Homo sapiensMutation(s): 1 
Gene Names: GJB2
Find proteins for P29033 (Homo sapiens)
Go to Gene View: GJB2
Go to UniProtKB:  P29033
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
ACE
Query on ACE
A
NON-POLYMERC2 H4 O

--

Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Submitted: 20 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical SciencesUnited StatesGM098584

Revision History 

  • Version 1.0: 2016-09-28
    Type: Initial release
  • Version 1.1: 2017-09-20
    Type: Author supporting evidence, Database references, Structure summary