Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Cyclic - C4  (3D View)
Global Stoichiometry: Homo 4-mer - A4 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 38.03 kDa 
• Atom Count: 2843 
• Modelled Residue Count: 327 
• Deposited Residue Count: 327 
• Unique protein chains: 1

3EAU

Voltage-dependent K+ channel beta subunit in complex with cortisone

• PDB DOI: 10.2210/pdb3EAU/pdb

• Classification: TRANSPORT PROTEIN, oxidoreductase
• Organism(s): Rattus norvegicus
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2008-08-26 Released: 2008-09-23 
• Deposition Author(s): Pan, Y., Weng, J., Kabaleeswaran, V., Li, H., Cao, Y., Bhosle, R.C., Zhou, M.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.82 Å
• R-Value Free: 0.206 
• R-Value Work: 0.194 
• R-Value Observed: 0.194 

Literature

Cortisone dissociates the Shaker family K+ channels from their beta subunits.

Pan, Y., Weng, J., Kabaleeswaran, V., Li, H., Cao, Y., Bhosle, R.C., Zhou, M.

(2008) Nat Chem Biol 4: 708-714

• PubMed: 18806782 
• DOI: 10.1038/nchembio.114
• Primary Citation of Related Structures:  
  3EAU, 3EB3, 3EB4


• PubMed Abstract: 
  

The Shaker family voltage-dependent potassium channels (Kv1) are expressed in a wide variety of cells and are essential for cellular excitability. In humans, loss-of-function mutations of Kv1 channels lead to hyperexcitability and are directly linked to episodic ataxia and atrial fibrillation. All Kv1 channels assemble with beta subunits (Kv betas), and certain Kv betas, for example Kv beta 1, have an N-terminal segment that closes the channel by the N-type inactivation mechanism. In principle, dissociation of Kv beta 1, although never reported, should eliminate inactivation and thus potentiate Kv1 current. We found that cortisone increases rat Kv1 channel activity by binding to Kv beta 1. A crystal structure of the Kv beta-cortisone complex was solved to 1.82-A resolution and revealed novel cortisone binding sites. Further studies demonstrated that cortisone promotes dissociation of Kv beta. The new mode of channel modulation may be explored by native or synthetic ligands to fine-tune cellular excitability.

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Related Citations: 

• Structure of a voltage-dependent K+ channel beta subunit.
  Gulbis, J.M., Mann, S., MacKinnon, R.
  (1999) Cell 97: 943

• Structure of the cytoplasmic beta subunit-T1 assembly of voltage-dependent K+ channels.
  Gulbis, J.M., Zhou, M., Mann, S., MacKinnon, R.
  (2000) Science 289: 123

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Organizational Affiliation: 

Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, 630 West 168th Street, New York, New York 10032, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Voltage-gated potassium channel subunit beta-2	A	327	Rattus norvegicus	Mutation(s): 0  Gene Names: Kcnab2, Ckbeta2, Kcnb3 EC: 1.1.1
UniProt
Find proteins for P62483 (Rattus norvegicus) Explore P62483  Go to UniProtKB:  P62483

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
NDP	B [auth A]	NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE C21 H30 N7 O17 P3 ACFIXJIJDZMPPO-NNYOXOHSSA-N
PDN	C [auth A], D [auth A]	17,21-DIHYDROXYPREGNA-1,4-DIENE-3,11,20-TRIONE C21 H26 O5 WZTZVUUYKIOIRV-LMZHSBCYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.82 Å
• R-Value Free: 0.206 
• R-Value Work: 0.194 
• R-Value Observed: 0.194 
• Space Group: I 4 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 113.035	α = 90
b = 113.035	β = 90
c = 147.013	γ = 90

Software Package:

Software Name	Purpose
ADSC	data collection
CNS	refinement
HKL-2000	data reduction
SCALEPACK	data scaling
CNS	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2008-08-26 
• Released Date: 2008-09-23 
Deposition Author(s): Pan, Y., Weng, J., Kabaleeswaran, V., Li, H., Cao, Y., Bhosle, R.C., Zhou, M.

Revision History  

• Version 1.0: 2008-09-23
  Type: Initial release
  
• Version 1.1: 2011-07-13
  Changes: Version format compliance