2IH1

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.233 
  • R-Value Observed: 0.233 

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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:  
    2IH1, 2IH3

  • 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: kcsAskc1
Membrane Entity: Yes 
UniProt
Find proteins for P0A334 (Streptomyces lividans)
Explore P0A334 
Go to UniProtKB:  P0A334
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Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.233 
  • R-Value Observed: 0.233 
  • Space Group: I 4
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 156.391α = 90
b = 156.391β = 90
c = 75.671γ = 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