1KPK

Crystal Structure of the ClC Chloride Channel from E. coli

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.5 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.290 

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This is version 1.2 of the entry. See complete history. 

Literature

X-ray structure of a ClC chloride channel at 3.0 A reveals the molecular basis of anion selectivity.

Dutzler, R., Campbell, E.B., Cadene, M., Chait, B.T., MacKinnon, R.

(2002) Nature 415: 287-294

  • DOI: 10.1038/415287a
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • The ClC chloride channels catalyse the selective flow of Cl- ions across cell membranes, thereby regulating electrical excitation in skeletal muscle and the flow of salt and water across epithelial barriers. Genetic defects in ClC Cl- channels underl ...

    The ClC chloride channels catalyse the selective flow of Cl- ions across cell membranes, thereby regulating electrical excitation in skeletal muscle and the flow of salt and water across epithelial barriers. Genetic defects in ClC Cl- channels underlie several familial muscle and kidney diseases. Here we present the X-ray structures of two prokaryotic ClC Cl- channels from Salmonella enterica serovar typhimurium and Escherichia coli at 3.0 and 3.5 A, respectively. Both structures reveal two identical pores, each pore being formed by a separate subunit contained within a homodimeric membrane protein. Individual subunits are composed of two roughly repeated halves that span the membrane with opposite orientations. This antiparallel architecture defines a selectivity filter in which a Cl- ion is stabilized by electrostatic interactions with alpha-helix dipoles and by chemical coordination with nitrogen atoms and hydroxyl groups. These findings provide a structural basis for further understanding the function of ClC Cl- channels, and establish the physical and chemical basis of their anion selectivity.

    Organizational Affiliation: 

    Howard Hughes Medical Institute, Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
putative channel transporter
A, B, C, D, E, F
473Escherichia coli (strain K12)Gene Names: clcA (eriC, yadQ)
Membrane protein
mpstruct		Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group: 
H+/Cl-Exchange Transporters		Protein: 
H+/Cl- Exchange Transporter
Find proteins for P37019 (Escherichia coli (strain K12))
Go to UniProtKB:  P37019
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.5 Å
  • R-Value Free: 0.301 
  • R-Value Work: 0.290 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 105.660α = 90.00
b = 152.525β = 90.00
c = 263.064γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
DENZOdata reduction
AMoREphasing
CNSrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-01-23
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance