1JO6

Solution structure of the cytoplasmic N-terminus of the BK beta-subunit KCNMB2


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 30 
  • Conformers Submitted: 24 
  • 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

NMR structure of the "ball-and-chain" domain of KCNMB2, the beta 2-subunit of large conductance Ca2+- and voltage-activated potassium channels.

Bentrop, D.Beyermann, M.Wissmann, R.Fakler, B.

(2001) J.Biol.Chem. 276: 42116-42121

  • DOI: 10.1074/jbc.M107118200

  • PubMed Abstract: 
  • The auxiliary beta-subunit KCNMB2 (beta(2)) endows the non-inactivating large conductance Ca(2+)- and voltage-dependent potassium (BK) channel with fast inactivation. This process is mediated by the N terminus of KCNMB2 and closely resembles the "bal ...

    The auxiliary beta-subunit KCNMB2 (beta(2)) endows the non-inactivating large conductance Ca(2+)- and voltage-dependent potassium (BK) channel with fast inactivation. This process is mediated by the N terminus of KCNMB2 and closely resembles the "ball-and-chain"-type inactivation observed in voltage-gated potassium channels. Here we investigated the solution structure and function of the KCNMB2 N terminus (amino acids 1-45, BKbeta(2)N) using NMR spectroscopy and patch clamp recordings. BKbeta(2)N completely inactivated BK channels when applied to the cytoplasmic side; its interaction with the BK alpha-subunit is characterized by a particularly slow dissociation rate and an affinity in the upper nanomolar range. The BKbeta(2)N structure comprises two domains connected by a flexible linker: the pore-blocking "ball domain" (formed by residues 1-17) and the "chain domain" (between residues 20-45) linking it to the membrane segment of KCNMB2. The ball domain is made up of a flexible N terminus anchored at a well ordered loop-helix motif. The chain domain consists of a 4-turn helix with an unfolded linker at its C terminus. These structural properties explain the functional characteristics of BKbeta(2)N-mediated inactivation.


    Related Citations: 
    • Molecular basis of fast inactivation in voltage and Ca2+-activated K+ channels: a transmembrane beta-subunit homolog
      Wallner, M.,Meera, P.,Toro, L.
      (1999) Proc.Natl.Acad.Sci.USA 96: 4137
    • Molecular basis for the inactivation of Ca2+- and voltage-dependent BK channels in adrenal chromaffin cells and rat insulinoma tumor cells
      Xia, X.M.,Ding, J.P.,Lingle, C.J.
      (1999) J.Neurosci. 19: 5255


    Organizational Affiliation

    Department of Physiology II, University of Tübingen, Ob dem Himmelreich 7, 72074 Tübingen, Germany. detlef.bentrop@uni-tuebingen.de




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
potassium large conductance calcium-activated channel, subfamily M, beta member 2
A
45Homo sapiensMutation(s): 0 
Gene Names: KCNMB2
Find proteins for Q9Y691 (Homo sapiens)
Go to Gene View: KCNMB2
Go to UniProtKB:  Q9Y691
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 30 
  • Conformers Submitted: 24 
  • Selection Criteria: structures with the least restraint violations,target function 
  • Olderado: 1JO6 Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-11-16
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance