5E1A

Structure of KcsA with L24C/R117C mutations


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.4 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.247 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Conformational heterogeneity in closed and open states of the KcsA potassium channel in lipid bicelles.

Kim, D.M.Dikiy, I.Upadhyay, V.Posson, D.J.Eliezer, D.Nimigean, C.M.

(2016) J.Gen.Physiol. 148: 119-132

  • DOI: 10.1085/jgp.201611602

  • PubMed Abstract: 
  • The process of ion channel gating-opening and closing-involves local and global structural changes in the channel in response to external stimuli. Conformational changes depend on the energetic landscape that underlies the transition between closed a ...

    The process of ion channel gating-opening and closing-involves local and global structural changes in the channel in response to external stimuli. Conformational changes depend on the energetic landscape that underlies the transition between closed and open states, which plays a key role in ion channel gating. For the prokaryotic, pH-gated potassium channel KcsA, closed and open states have been extensively studied using structural and functional methods, but the dynamics within each of these functional states as well as the transition between them is not as well understood. In this study, we used solution nuclear magnetic resonance (NMR) spectroscopy to investigate the conformational transitions within specific functional states of KcsA. We incorporated KcsA channels into lipid bicelles and stabilized them into a closed state by using either phosphatidylcholine lipids, known to favor the closed channel, or mutations designed to trap the channel shut by disulfide cross-linking. A distinct state, consistent with an open channel, was uncovered by the addition of cardiolipin lipids. Using selective amino acid labeling at locations within the channel that are known to move during gating, we observed at least two different slowly interconverting conformational states for both closed and open channels. The pH dependence of these conformations and the predictable disruptions to this dependence observed in mutant channels with altered pH sensing highlight the importance of conformational heterogeneity for KcsA gating.


    Organizational Affiliation

    Department of Anesthesiology, Weill Cornell Medical College, New York, NY 10065.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
antibody Fab fragment heavy chain
A
219N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
antibody Fab fragment light chain
B
212N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
pH-gated potassium channel KcsA
C
124Streptomyces lividansMutation(s): 2 
Gene Names: kcsA (skc1)
Find proteins for P0A334 (Streptomyces lividans)
Go to UniProtKB:  P0A334
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
K
Query on K

Download SDF File 
Download CCD File 
C
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.4 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.247 
  • Space Group: I 4
Unit Cell:
Length (Å)Angle (°)
a = 154.794α = 90.00
b = 154.794β = 90.00
c = 74.479γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
XSCALEdata scaling
PHENIXrefinement
PHENIXphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical SciencesUnited States5RO1GM088352

Revision History 

  • Version 1.0: 2016-07-13
    Type: Initial release
  • Version 1.1: 2016-08-31
    Type: Database references
  • Version 1.2: 2017-09-06
    Type: Author supporting evidence, Derived calculations