Biological Assembly 1  

 3D View: Structure | 1D-3D View | Validation Report

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

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 11.49 kDa 
• Atom Count: 776 
• Modelled Residue Count: 87 
• Deposited Residue Count: 95 
• Unique protein chains: 1

1A68

CRYSTAL STRUCTURE OF THE TETRAMERIZATION DOMAIN OF THE SHAKER POTASSIUM CHANNEL

• PDB DOI: 10.2210/pdb1A68/pdb

• Classification: POTASSIUM CHANNELS
• Organism(s): Aplysia californica
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 1998-03-06 Released: 1998-06-10 
• Deposition Author(s): Kreusch, A., Pfaffinger, P.J., Stevens, C.F., Choe, S.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free: 0.241 
• R-Value Work: 0.200 
• R-Value Observed: 0.200 

Literature

Crystal structure of the tetramerization domain of the Shaker potassium channel.

Kreusch, A., Pfaffinger, P.J., Stevens, C.F., Choe, S.

(1998) Nature 392: 945-948

• PubMed: 9582078 
• DOI: 10.1038/31978
• Primary Citation of Related Structures:  
  1A68


• PubMed Abstract: 
  

Voltage-dependent, ion-selective channels such as Na+, Ca2+ and K+ channel proteins function as tetrameric assemblies of identical or similar subunits. The clustering of four subunits is thought to create an aqueous pore centred at the four-fold symmetry axis. The highly conserved, amino-terminal cytoplasmic domain (approximately 130 amino acids) immediately preceding the first putative transmembrane helix S1 is designated T1. It is known to confer specificity for tetramer formation, so the heteromeric assembly of K+-channel subunits is an important mechanism for the observed channel diversity. We have determined the crystal structure of the T1 domain of a Shaker potassium channel at 1.55 A resolution. The structure reveals that four identical subunits are arranged in a four-fold symmetry surrounding a centrally located pore about 20 A in length. Subfamily-specific assembly is provided primarily by polar interactions encoded in a conserved set of amino acids at its tetramerization interface. Most highly conserved amino acids in the T1 domain of all known potassium channels are found in the core of the protein, indicating a common structural framework for the tetramer assembly.

---

Organizational Affiliation: 

Structural Biology, The Salk Institute, La Jolla, California 92037, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
POTASSIUM CHANNEL KV1.1	A	95	Aplysia californica	Mutation(s): 0
UniProt
Find proteins for Q16968 (Aplysia californica) Explore Q16968  Go to UniProtKB:  Q16968

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free: 0.241 
• R-Value Work: 0.200 
• R-Value Observed: 0.200 
• Space Group: I 4

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 51.034	α = 90
b = 51.034	β = 90
c = 65.605	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
DENZO	data reduction
SCALEPACK	data scaling
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1998-03-06 
• Released Date: 1998-06-10 
Deposition Author(s): Kreusch, A., Pfaffinger, P.J., Stevens, C.F., Choe, S.

Revision History  

• Version 1.0: 1998-06-10
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance