1P7B

Crystal structure of an inward rectifier potassium channel

• PDB DOI: https://doi.org/10.2210/pdb1P7B/pdb

• Classification: METAL TRANSPORT
• Organism(s): Burkholderia pseudomallei
• Expression System: Escherichia coli
• Mutation(s): No 
• Membrane Protein: Yes  OPMPDBTMMemProtMDmpstruc


• Deposited: 2003-05-01 Released: 2003-06-17 
• Deposition Author(s): Kuo, A., Gulbis, J.M., Antcliff, J.F., Rahman, T., Lowe, E.D., Zimmer, J., Cuthbertson, J., Ashcroft, F.M., Ezaki, T., Doyle, D.A.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 3.65 Å
• R-Value Free: 0.329 
• R-Value Work: 0.295 
• R-Value Observed: 0.297 

Re-refinement Note

A newer entry is available that reflects an alternative modeling of the original data: 2WLL

Literature

Crystal structure of the potassium channel KirBac1.1 in the closed state.

Kuo, A., Gulbis, J.M., Antcliff, J.F., Rahman, T., Lowe, E.D., Zimmer, J., Cuthbertson, J., Ashcroft, F.M., Ezaki, T., Doyle, D.A.

(2003) Science 300: 1922-1926

• PubMed: 12738871 
• DOI: https://doi.org/10.1126/science.1085028
• Primary Citation of Related Structures:  
  1P7B


• PubMed Abstract: 
  

  The KirBac1.1 channel belongs to the inward-rectifier family of potassium channels. Here we report the structure of the entire prokaryotic Kir channel assembly, in the closed state, refined to a resolution of 3.65 angstroms. We identify the main activation gate and structural elements involved in gating. On the basis of structural evidence presented here, we suggest that gating involves coupling between the intracellular and membrane domains. This further suggests that initiation of gating by membrane or intracellular signals represents different entry points to a common mechanistic pathway.

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Organizational Affiliation: 

University of Oxford, Department of Biochemistry, Laboratory of Molecular Biophysics, South Parks Road, Oxford OX1 3QU, UK.

Biological Assembly 1  

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

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

Macromolecule Content

• Total Structure Weight: 74.51 kDa 
• Atom Count: 4,059 
• Modelled Residue Count: 516 
• Deposited Residue Count: 666 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
integral membrane channel and cytosolic domains	A, B	333	Burkholderia pseudomallei	Mutation(s): 0  Gene Names: chromosome 1 kirbac1.1 Membrane Entity: Yes
UniProt
Find proteins for P83698 (Burkholderia pseudomallei) Explore P83698  Go to UniProtKB:  P83698

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
K	C [auth A], D [auth A], E [auth A], F [auth B]	POTASSIUM ION K NPYPAHLBTDXSSS-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 3.65 Å
• R-Value Free: 0.329 
• R-Value Work: 0.295 
• R-Value Observed: 0.297 
• Space Group: I 2 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 92.84	α = 90
b = 105.62	β = 90
c = 258.63	γ = 90

Software Package:

Software Name	Purpose
MOSFLM	data reduction
SCALA	data scaling
SHELXS	phasing
MLPHARE	phasing
DM	model building
RAVE	model building
CNS	refinement
CCP4	data scaling
DM	phasing
RAVE	phasing

Structure Validation

Entry History 

Deposition Data

• Released Date: 2003-06-17 
Deposition Author(s): Kuo, A., Gulbis, J.M., Antcliff, J.F., Rahman, T., Lowe, E.D., Zimmer, J., Cuthbertson, J., Ashcroft, F.M., Ezaki, T., Doyle, D.A.

Revision History  

• Version 1.0: 2003-06-17
  Type: Initial release
  
• Version 1.1: 2008-04-29
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Derived calculations, Version format compliance
• Version 1.3: 2024-02-14
  Changes: Data collection, Database references, Derived calculations