2IH3

Ion selectivity in a semi-synthetic K+ channel locked in the conductive conformation

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.72 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.233 
  • R-Value Observed: 0.233 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history. 


Literature

Ion Selectivity in a Semisynthetic K+ Channel Locked in the Conductive Conformation.

Valiyaveetil, F.I., Leonetti, M., Muir, T.W., Mackinnon, R.

(2006) Science 314: 1004-1007

  • DOI: 10.1126/science.1133415
  • Primary Citation of Related Structures:  
    2IH3, 2IH1

  • PubMed Abstract: 

    • Potassium channels are K+-selective protein pores in cell membrane. The selectivity filter is the functional unit that allows K+ channels to distinguish potassium (K+) and sodium (Na+) ions. The filter's structure depends on whether K+ or Na+ ions are bound inside it ...

    Potassium channels are K+-selective protein pores in cell membrane. The selectivity filter is the functional unit that allows K+ channels to distinguish potassium (K+) and sodium (Na+) ions. The filter's structure depends on whether K+ or Na+ ions are bound inside it. We synthesized a K+ channel containing the d-enantiomer of alanine in place of a conserved glycine and found by x-ray crystallography that its filter maintains the K+ (conductive) structure in the presence of Na+ and very low concentrations of K+. This channel conducts Na+ in the absence of K+ but not in the presence of K+. These findings demonstrate that the ability of the channel to adapt its structure differently to K+ and Na+ is a fundamental aspect of ion selectivity, as is the ability of multiple K+ ions to compete effectively with Na+ for the conductive filter.

    Organizational Affiliation: 

    Laboratories of Molecular Neurobiology and Biophysics and Synthetic Protein Chemistry, Rockefeller University and Howard Hughes Medical Institute, 1230 York Avenue, New York, NY 10021, USA.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
FAB Heavy ChainA219Mus musculusMutation(s): 0 
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
FAB Light ChainB212Mus musculusMutation(s): 0 
Protein Feature View
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Voltage-gated potassium channelC122Streptomyces lividansMutation(s): 3 
Gene Names: kcsA, skc1
Find proteins for P0A334 (Streptomyces lividans)
Explore P0A334 
Go to UniProtKB:  P0A334
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.72 Å
  • R-Value Free: 0.242 
  • R-Value Work: 0.233 
  • R-Value Observed: 0.233 
  • Space Group: I 4
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 155.724α = 90
b = 155.724β = 90
c = 75.741γ = 90
Software Package:
Software NamePurpose
CNSrefinement
PDB_EXTRACTdata extraction
CBASSdata collection
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-11-21
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2011-11-16
    Changes: Atomic model