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 

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

  • 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 t ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ATP-SENSITIVE INWARD RECTIFIER POTASSIUM CHANNEL 10
A
301Magnetospirillum magnetotacticumMutation(s): 1 
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Channels: Potassium, Sodium, & Proton Ion-Selective
Protein: 
KirBac3.1 Inward-Rectifier Potassium channel (semi-latched)
Find proteins for D9N164 (Magnetospirillum magnetotacticum)
Go to UniProtKB:  D9N164
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

Download SDF File 
Download CCD File 
A
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

Download SDF File 
Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.05 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.220 
  • Space Group: P 4 21 2
Unit Cell:
Length (Å)Angle (°)
a = 106.240α = 90.00
b = 106.240β = 90.00
c = 89.800γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
BUSTERrefinement
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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