Macromolecule Content

• Total Structure Weight: 5380.06 
• Atom Count: 377 
• Residue Count: 45 
• Unique protein chains: 1

1JO6

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

• DOI: 10.2210/pdb1JO6/pdb
• BMRB: 5092

• Classification: METAL TRANSPORT MEMBRANE PROTEIN
• Organism(s): Homo sapiens


• Deposited: 2001-07-27 Released: 2001-11-16 
• Deposition Author(s): Bentrop, D., Beyermann, M., Wissmann, R., Fakler, B.

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Experimental Data Snapshot

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

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

• PubMed: 11517232 
• 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 "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.

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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




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Organizational Affiliation: 

Department of Physiology II, University of Tübingen, Ob dem Himmelreich 7, 72074 Tübingen, Germany. [e-mail]

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
potassium large conductance calcium-activated channel, subfamily M, beta member 2	A	45	Homo sapiens	Mutation(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

Entry History 

Deposition Data

• Deposited Date: 2001-07-27 
• Released Date: 2001-11-16 
• Deposition Author(s): Bentrop, D., Beyermann, M., Wissmann, R., Fakler, B.

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