Biological Assembly 1  

 3D View: Structure | Electron Density

Global Symmetry: Cyclic - C3  (3D View)
Global Stoichiometry: Homo 3-mer - A3 

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

Macromolecule Content

• Total Structure Weight: 15.74 kDa 
• Atom Count: 1185 
• Modelled Residue Count: 138 
• Deposited Residue Count: 138 
• Unique protein chains: 1

3SWY

CNGA3 626-672 containing CLZ domain

• DOI: 10.2210/pdb3SWY/pdb

• Classification: TRANSPORT PROTEIN
• Organism(s): Homo sapiens
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2011-07-14 Released: 2011-09-14 
• Deposition Author(s): Shuart, N.G., Haitin, Y., Camp, S.S., Black, K.D., Zagotta, W.N.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free: 0.224 
• R-Value Work: 0.197 
• R-Value Observed: 0.198 

Literature

Molecular mechanism for 3:1 subunit stoichiometry of rod cyclic nucleotide-gated ion channels.

Shuart, N.G., Haitin, Y., Camp, S.S., Black, K.D., Zagotta, W.N.

(2011) Nat Commun 2: 457-457

• PubMed: 21878911 
• DOI: 10.1038/ncomms1466
• Primary Citation of Related Structures:  
  3SWF, 3SWY


• PubMed Abstract: 
  

Molecular determinants of ion channel tetramerization are well characterized, but those involved in heteromeric channel assembly are less clearly understood. The heteromeric composition of native channels is often precisely controlled. Cyclic nucleotide-gated (CNG) channels from rod photoreceptors exhibit a 3:1 stoichiometry of CNGA1 and CNGB1 subunits that tunes the channels for their specialized role in phototransduction. Here we show, using electrophysiology, fluorescence, biochemistry, and X-ray crystallography, that the mechanism for this controlled assembly is the formation of a parallel 3-helix coiled-coil domain of the carboxy-terminal leucine zipper region of CNGA1 subunits, constraining the channel to contain three CNGA1 subunits, followed by preferential incorporation of a single CNGB1 subunit. Deletion of the carboxy-terminal leucine zipper domain relaxed the constraint and permitted multiple CNGB1 subunits in the channel. The X-ray crystal structures of the parallel 3-helix coiled-coil domains of CNGA1 and CNGA3 subunits were similar, suggesting that a similar mechanism controls the stoichiometry of cone CNG channels.

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Organizational Affiliation: 

Howard Hughes Medical Institute and Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Cyclic nucleotide-gated cation channel alpha-3	A, B, C	46	Homo sapiens	Mutation(s): 0  Gene Names: CNCG3, CNGA3
Find proteins for Q16281 (Homo sapiens) Explore Q16281  Go to UniProtKB:  Q16281
NIH Common Fund Data Resources
PHAROS:  Q16281 GTEx:  ENSG00000144191

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.90 Å
• R-Value Free: 0.224 
• R-Value Work: 0.197 
• R-Value Observed: 0.198 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 36.75	α = 90
b = 37.65	β = 110.88
c = 49.58	γ = 90

Software Package:

Software Name	Purpose
MOSFLM	data reduction
SCALA	data scaling
PHASER	phasing
PHENIX	refinement
PDB_EXTRACT	data extraction
BOS	data collection

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2011-07-14 
• Released Date: 2011-09-14 
Deposition Author(s): Shuart, N.G., Haitin, Y., Camp, S.S., Black, K.D., Zagotta, W.N.

Revision History  

• Version 1.0: 2011-09-14
  Type: Initial release