1G4Y

1.60 A CRYSTAL STRUCTURE OF THE GATING DOMAIN FROM SMALL CONDUCTANCE POTASSIUM CHANNEL COMPLEXED WITH CALCIUM-CALMODULIN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.221 
  • R-Value Observed: 0.212 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Structure of the gating domain of a Ca2+-activated K+ channel complexed with Ca2+/calmodulin.

Schumacher, M.A.Rivard, A.F.Bachinger, H.P.Adelman, J.P.

(2001) Nature 410: 1120-1124

  • DOI: https://doi.org/10.1038/35074145
  • Primary Citation of Related Structures:  
    1G4Y

  • PubMed Abstract: 

    Small-conductance Ca2+-activated K+ channels (SK channels) are independent of voltage and gated solely by intracellular Ca2+. These membrane channels are heteromeric complexes that comprise pore-forming alpha-subunits and the Ca2+-binding protein calmodulin (CaM). CaM binds to the SK channel through the CaM-binding domain (CaMBD), which is located in an intracellular region of the alpha-subunit immediately carboxy-terminal to the pore. Channel opening is triggered when Ca2+ binds the EF hands in the N-lobe of CaM. Here we report the 1.60 A crystal structure of the SK channel CaMBD/Ca2+/CaM complex. The CaMBD forms an elongated dimer with a CaM molecule bound at each end; each CaM wraps around three alpha-helices, two from one CaMBD subunit and one from the other. As only the CaM N-lobe has bound Ca2+, the structure provides a view of both calcium-dependent and -independent CaM/protein interactions. Together with biochemical data, the structure suggests a possible gating mechanism for the SK channel.


  • Organizational Affiliation

    Vollum Institute, Oregon Health Sciences University, Portland, Oregon 97201-3098, USA. schumacm@ohsu.edu


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
CALCIUM-ACTIVATED POTASSIUM CHANNEL RSK2A [auth B]101Rattus norvegicusMutation(s): 0 
Gene Names: RAT
UniProt
Find proteins for P70604 (Rattus norvegicus)
Explore P70604 
Go to UniProtKB:  P70604
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP70604
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
CALMODULINB [auth R]148Rattus norvegicusMutation(s): 0 
Gene Names: RAT
UniProt
Find proteins for P0DP29 (Rattus norvegicus)
Explore P0DP29 
Go to UniProtKB:  P0DP29
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0DP29
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download Ideal Coordinates CCD File 
C [auth B]SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
CA
Query on CA

Download Ideal Coordinates CCD File 
D [auth R],
E [auth R]
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.221 
  • R-Value Observed: 0.212 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 77.65α = 90
b = 66.69β = 93.7
c = 64.69γ = 90
Software Package:
Software NamePurpose
PHASESphasing
CNSrefinement
MOSFLMdata reduction
CCP4data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-05-09
    Type: Initial release
  • Version 1.1: 2008-04-27
    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
  • Version 1.4: 2024-02-07
    Changes: Data collection, Database references, Derived calculations