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 1.3 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: https://doi.org/10.1074/jbc.M107118200
  • Primary Citation of Related Structures:  
    1JO6

  • 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 "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.


  • Organizational Affiliation

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


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
potassium large conductance calcium-activated channel, subfamily M, beta member 245N/AMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for Q9Y691 (Homo sapiens)
Explore Q9Y691 
Go to UniProtKB:  Q9Y691
PHAROS:  Q9Y691
GTEx:  ENSG00000197584 
Entity Groups  
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UniProt GroupQ9Y691
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

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

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-11-16
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2022-02-23
    Changes: Data collection, Database references, Derived calculations