3ZRS

X-ray crystal structure of a KirBac potassium channel highlights a mechanism of channel opening at the bundle-crossing gate.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.05 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.222 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structure of a Kirbac Potassium Channel with an Open Bundle Crossing Indicates a Mechanism of Channel Gating

Bavro, V.N.De Zorzi, R.Schmidt, M.R.Muniz, J.R.C.Zubcevic, L.Sansom, M.S.P.Venien-Bryan, C.Tucker, S.J.

(2012) Nat Struct Mol Biol 19: 158

  • DOI: 10.1038/nsmb.2208
  • Primary Citation of Related Structures:  
    3ZRS

  • PubMed Abstract: 
  • KirBac channels are prokaryotic homologs of mammalian inwardly rectifying (Kir) potassium channels, and recent crystal structures of both Kir and KirBac channels have provided major insight into their unique structural architecture. However, all of the available structures are closed at the helix bundle crossing, and therefore the structural mechanisms that control opening of their primary activation gate remain unknown ...

    KirBac channels are prokaryotic homologs of mammalian inwardly rectifying (Kir) potassium channels, and recent crystal structures of both Kir and KirBac channels have provided major insight into their unique structural architecture. However, all of the available structures are closed at the helix bundle crossing, and therefore the structural mechanisms that control opening of their primary activation gate remain unknown. In this study, we engineered the inner pore-lining helix (TM2) of KirBac3.1 to trap the bundle crossing in an apparently open conformation and determined the crystal structure of this mutant channel to 3.05 Å resolution. Contrary to previous speculation, this new structure suggests a mechanistic model in which rotational 'twist' of the cytoplasmic domain is coupled to opening of the bundle-crossing gate through a network of inter- and intrasubunit interactions that involve the TM2 C-linker, slide helix, G-loop and the CD loop.


    Organizational Affiliation

    Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ATP-SENSITIVE INWARD RECTIFIER POTASSIUM CHANNEL 10A301Magnetospirillum magnetotacticumMutation(s): 1 
Membrane Entity: Yes 
UniProt
Find proteins for D9N164 (Magnetospirillum magnetotacticum)
Explore D9N164 
Go to UniProtKB:  D9N164
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupD9N164
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.05 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.220 
  • R-Value Observed: 0.222 
  • Space Group: P 4 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 106.24α = 90
b = 106.24β = 90
c = 89.8γ = 90
Software Package:
Software NamePurpose
BUSTERrefinement
MOSFLMdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-01-11
    Type: Initial release
  • Version 1.1: 2012-02-15
    Changes: Other