1QX7

Crystal structure of apoCaM bound to the gating domain of small conductance Ca2+-activated potassium channel


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.09 Å
  • R-Value Free: 0.308 
  • R-Value Work: 0.286 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structures of apocalmodulin and an apocalmodulin/SK potassium channel gating domain complex.

Schumacher, M.A.Crum, M.Miller, M.C.

(2004) STRUCTURE 12: 849-860

  • DOI: 10.1016/j.str.2004.03.017
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Small conductance Ca2+-activated K+ channels (SK channels) are composed of the pore-forming alpha subunit and calmodulin (CaM). CaM binds to a region of the alpha subunit called the CaM binding domain (CaMBD), located intracellular and immediately C- ...

    Small conductance Ca2+-activated K+ channels (SK channels) are composed of the pore-forming alpha subunit and calmodulin (CaM). CaM binds to a region of the alpha subunit called the CaM binding domain (CaMBD), located intracellular and immediately C-terminal to the inner helix gate, in either the presence or absence of Ca2+. SK gating occurs when Ca2+ binds the N lobe of CaM thereby transmitting the signal to the attached inner helix gate to open. Here we present crystal structures of apoCaM and apoCaM/SK2 CaMBD complex. Several apoCaM crystal forms with multiple (12) packing environments reveal the same EF hand domain-swapped dimer providing potentially new insight into CaM regulation. The apoCaM/SK2 CaMBD structure, combined with our Ca2+/CaM/CaMBD structure suggests that Ca2+ binding induces folding and dimerization of the CaMBD, which causes large CaMBD-CaM C lobe conformational changes, including a >90 degrees rotation of the region of the CaMBD directly connected to the gate.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, OR 97239 USA. schumacm@ohsu.edu




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calmodulin
I, R, A, B, M
148Rattus norvegicusMutation(s): 0 
Gene 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
D
85Rattus norvegicusMutation(s): 0 
Gene Names: Kcnn2
Find proteins for P70604 (Rattus norvegicus)
Go to UniProtKB:  P70604
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B, I, M, R
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.09 Å
  • R-Value Free: 0.308 
  • R-Value Work: 0.286 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 79.930α = 90.00
b = 79.930β = 90.00
c = 220.800γ = 90.00
Software Package:
Software NamePurpose
CCP4data scaling
MOSFLMdata reduction
CNSrefinement
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-08-31
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance