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: 1.6 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.221 

wwPDB Validation 3D Report Full Report


This is version 1.3 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: 10.1038/35074145

  • 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 cal ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CALCIUM-ACTIVATED POTASSIUM CHANNEL RSK2
B
101Rattus norvegicusGene Names: Kcnn2
Find proteins for P70604 (Rattus norvegicus)
Go to UniProtKB:  P70604
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
CALMODULIN
R
148Rattus norvegicusGene Names: Calm1 (Calm, Cam, Cam1, CaMI)
Find proteins for P0DP29 (Rattus norvegicus)
Go to UniProtKB:  P0DP29
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
CA
Query on CA

Download SDF File 
Download CCD File 
R
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.6 Å
  • R-Value Free: 0.251 
  • R-Value Work: 0.221 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 77.650α = 90.00
b = 66.690β = 93.70
c = 64.690γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
CCP4data scaling
PHASESphasing
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-05-09
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance
  • Version 1.3: 2011-11-16
    Type: Atomic model