3PJS

Mechanism of Activation Gating in the Full-Length KcsA K+ Channel


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.8 Å
  • R-Value Free: 0.332 
  • R-Value Work: 0.281 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Mechanism of activation gating in the full-length KcsA K+ channel.

Uysal, S.Cuello, L.G.Cortes, D.M.Koide, S.Kossiakoff, A.A.Perozo, E.

(2011) Proc.Natl.Acad.Sci.USA 108: 11896-11899

  • DOI: 10.1073/pnas.1105112108

  • PubMed Abstract: 
  • Using a constitutively active channel mutant, we solved the structure of full-length KcsA in the open conformation at 3.9 Å. The structure reveals that the activation gate expands about 20 Å, exerting a strain on the bulge helices in the C-terminal d ...

    Using a constitutively active channel mutant, we solved the structure of full-length KcsA in the open conformation at 3.9 Å. The structure reveals that the activation gate expands about 20 Å, exerting a strain on the bulge helices in the C-terminal domain and generating side windows large enough to accommodate hydrated K(+) ions. Functional and spectroscopic analysis of the gating transition provides direct insight into the allosteric coupling between the activation gate and the selectivity filter. We show that the movement of the inner gate helix is transmitted to the C-terminus as a straightforward expansion, leading to an upward movement and the insertion of the top third of the bulge helix into the membrane. We suggest that by limiting the extent to which the inner gate can open, the cytoplasmic domain also modulates the level of inactivation occurring at the selectivity filter.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
FAB light chain
A, C
215N/AN/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
FAB heavy chain
B, D
224N/AN/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Voltage-gated potassium channel
K, L, M, N
166Streptomyces lividansGene Names: kcsA (skc1)
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Channels: Potassium, Sodium, & Proton Ion-Selective
Protein: 
KcsA Potassium channel, H+ gated
Find proteins for P0A334 (Streptomyces lividans)
Go to UniProtKB:  P0A334
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.8 Å
  • R-Value Free: 0.332 
  • R-Value Work: 0.281 
  • Space Group: I 2 2 2
Unit Cell:
Length (Å)Angle (°)
a = 118.266α = 90.00
b = 176.716β = 90.00
c = 340.466γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data reduction
MAR345dtbdata collection
CNSrefinement
HKL-2000data scaling
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-07-06
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2011-07-20
    Type: Database references
  • Version 1.3: 2011-08-03
    Type: Database references