3SJQ

Crystal structure of a small conductance potassium channel splice variant complexed with calcium-calmodulin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.170 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Structural basis for calmodulin as a dynamic calcium sensor.

Zhang, M.Abrams, C.Wang, L.Gizzi, A.He, L.Lin, R.Chen, Y.Loll, P.J.Pascal, J.M.Zhang, J.F.

(2012) Structure 20: 911-923

  • DOI: 10.1016/j.str.2012.03.019

  • PubMed Abstract: 
  • Calmodulin is a prototypical and versatile Ca(2+) sensor with EF hands as its high-affinity Ca(2+) binding domains. Calmodulin is present in all eukaryotic cells, mediating Ca(2+)-dependent signaling. Upon binding Ca(2+), calmodulin changes its confo ...

    Calmodulin is a prototypical and versatile Ca(2+) sensor with EF hands as its high-affinity Ca(2+) binding domains. Calmodulin is present in all eukaryotic cells, mediating Ca(2+)-dependent signaling. Upon binding Ca(2+), calmodulin changes its conformation to form complexes with a diverse array of target proteins. Despite a wealth of knowledge on calmodulin, little is known on how target proteins regulate calmodulin's ability to bind Ca(2+). Here, we take advantage of two splice variants of SK2 channels, which are activated by Ca(2+)-bound calmodulin but show different sensitivity to Ca(2+) for their activation. Protein crystal structures and other experiments show that, depending on which SK2 splice variant it binds to, calmodulin adopts drastically different conformations with different affinities for Ca(2+) at its C-lobe. Such target protein-induced conformational changes make calmodulin a dynamic Ca(2+) sensor capable of responding to different Ca(2+) concentrations in cellular Ca(2+) signaling.


    Organizational Affiliation

    Department of Molecular Physiology and Biophysics, Jefferson Medical College, Philadelphia, PA 19107, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calmodulin
A, B
149Rattus norvegicusGene Names: Calm2 (Cam2, Camb, CaMII)
Find proteins for P0DP30 (Rattus norvegicus)
Go to UniProtKB:  P0DP30
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Small conductance calcium-activated potassium channel protein 2
C, D
87Rattus norvegicusGene Names: Kcnn2
Find proteins for P70604 (Rattus norvegicus)
Go to UniProtKB:  P70604
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B, C, D
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
GOL
Query on GOL

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Download CCD File 
A, B, D
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
CA
Query on CA

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Download CCD File 
A, B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
PHU
Query on PHU

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Download CCD File 
A, B, C, D
1-phenylurea
Phenylurea
C7 H8 N2 O
LUBJCRLGQSPQNN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.170 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 47.740α = 90.68
b = 65.630β = 110.45
c = 66.080γ = 111.02
Software Package:
Software NamePurpose
XDSdata reduction
PHENIXrefinement
CBASSdata collection
PHASERphasing
XDSdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-05-30
    Type: Initial release