1KKD

Solution structure of the calmodulin binding domain (CaMBD) of small conductance Ca2+-activated potassium channels (SK2)


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 300 
  • Conformers Submitted: 23 
  • Selection Criteria: structures with the least restraint violations,target function 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

A helical region in the C terminus of small-conductance Ca2+-activated K+ channels controls assembly with apo-calmodulin.

Wissmann, R.Bildl, W.Neumann, H.Rivard, A.F.Klocker, N.Weitz, D.Schulte, U.Adelman, J.P.Bentrop, D.Fakler, B.

(2002) J.Biol.Chem. 277: 4558-4564

  • DOI: 10.1074/jbc.M109240200

  • PubMed Abstract: 
  • Small conductance Ca(2+)-activated potassium (SK) channels underlie the afterhyperpolarization that follows the action potential in many types of central neurons. SK channels are voltage-independent and gated solely by intracellular Ca(2+) in the sub ...

    Small conductance Ca(2+)-activated potassium (SK) channels underlie the afterhyperpolarization that follows the action potential in many types of central neurons. SK channels are voltage-independent and gated solely by intracellular Ca(2+) in the submicromolar range. This high affinity for Ca(2+) results from Ca(2+)-independent association of the SK alpha-subunit with calmodulin (CaM), a property unique among the large family of potassium channels. Here we report the solution structure of the calmodulin binding domain (CaMBD, residues 396-487 in rat SK2) of SK channels using NMR spectroscopy. The CaMBD exhibits a helical region between residues 423-437, whereas the rest of the molecule lacks stable overall folding. Disruption of the helical domain abolishes constitutive association of CaMBD with Ca(2+)-free CaM, and results in SK channels that are no longer gated by Ca(2+). The results show that the Ca(2+)-independent CaM-CaMBD interaction, which is crucial for channel function, is at least in part determined by a region different in sequence and structure from other CaM-interacting proteins.


    Related Citations: 
    • Mechanism of calcium gating in small-conductance calcium-activated potassium channels
      Xia, X.-M.,Fakler, B.,Rivard, A.,Wayman, G.,Johnson-Pais, T.,Keen, J.E.,Ishii, T.,Hirschberg, B.,Bond, C.T.,Lutsenko, S.,Maylie, J.,Adelman, J.P.
      (1998) Nature 395: 503
    • Domains responsible for constitutive and Ca2+-dependent interactions between calmodulin and small conductance Ca2+- activated potassium channels
      Keen, J.E.,Khawaled, R.,Farrens, D.L.,Neelands, T.,Rivard, A.,Bond, C.T.,Janowsky, A.,Fakler, B.,Adelman, J.P.,Maylie, J.
      (1999) J.Neurosci. 19: 8830
    • Structure of the gating domain of a Ca2+-activated K+ channel complexed with Ca2+/calmodulin
      Schumacher, M.A.,Rivard, A.F.,Baechinger, H.P.,Adelman, J.P.
      (2001) Nature 410: 1120


    Organizational Affiliation

    Department of Physiology II, University of Tübingen, Ob dem Himmelreich 7, 72074 Tübingen, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Small conductance calcium-activated potassium channel protein 2
A
102Rattus norvegicusMutation(s): 0 
Gene Names: Kcnn2
Find proteins for P70604 (Rattus norvegicus)
Go to UniProtKB:  P70604
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 300 
  • Conformers Submitted: 23 
  • Selection Criteria: structures with the least restraint violations,target function 
  • Olderado: 1KKD Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-12-14
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance