5VMS

CryoEM structure of Xenopus KCNQ1 channel


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.7 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Cryo-EM Structure of a KCNQ1/CaM Complex Reveals Insights into Congenital Long QT Syndrome.

Sun, J.MacKinnon, R.

(2017) Cell 169: 1042-1050.e9

  • DOI: 10.1016/j.cell.2017.05.019

  • PubMed Abstract: 
  • KCNQ1 is the pore-forming subunit of cardiac slow-delayed rectifier potassium (I <sub>Ks </sub>) channels. Mutations in the kcnq1 gene are the leading cause of congenital long QT syndrome (LQTS). Here, we present the cryoelectron microscopy (cryo-EM) ...

    KCNQ1 is the pore-forming subunit of cardiac slow-delayed rectifier potassium (I Ks ) channels. Mutations in the kcnq1 gene are the leading cause of congenital long QT syndrome (LQTS). Here, we present the cryoelectron microscopy (cryo-EM) structure of a KCNQ1/calmodulin (CaM) complex. The conformation corresponds to an "uncoupled," PIP 2 -free state of KCNQ1, with activated voltage sensors and a closed pore. Unique structural features within the S4-S5 linker permit uncoupling of the voltage sensor from the pore in the absence of PIP 2 . CaM contacts the KCNQ1 voltage sensor through a specific interface involving a residue on CaM that is mutated in a form of inherited LQTS. Using an electrophysiological assay, we find that this mutation on CaM shifts the KCNQ1 voltage-activation curve. This study describes one physiological form of KCNQ1, depolarized voltage sensors with a closed pore in the absence of PIP 2 , and reveals a regulatory interaction between CaM and KCNQ1 that may explain CaM-mediated LQTS.


    Organizational Affiliation

    Laboratory of Molecular Neurobiology and Biophysics and Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.,Laboratory of Molecular Neurobiology and Biophysics and Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA. Electronic address: mackinn@rockefeller.edu.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Potassium voltage-gated channel subfamily KQT member 1
A
548Xenopus laevisMutation(s): 0 
Gene Names: kcnq1 (kvlqt1)
Membrane protein
mpstruc
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Channels: Potassium, Sodium, & Proton Ion-Selective
Protein: 
KCNQ1 cardiac slow-delayed rectifier K+ channel in complex with calmodulin
Find proteins for P70057 (Xenopus laevis)
Go to UniProtKB:  P70057
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Calmodulin
B
149Homo sapiensMutation(s): 0 
Gene Names: CALM1 (CALM, CAM, CAM1)
Membrane protein
mpstruc
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Channels: Potassium, Sodium, & Proton Ion-Selective
Protein: 
KCNQ1 cardiac slow-delayed rectifier K+ channel in complex with calmodulin
Find proteins for P0DP23 (Homo sapiens)
Go to Gene View: CALM1
Go to UniProtKB:  P0DP23
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CA
Query on CA

Download SDF File 
Download CCD File 
B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.7 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
Software Package:
Software NamePurpose
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data

  • Deposited Date: 2017-04-28 
  • Released Date: 2017-06-07 
  • Deposition Author(s): Mackinnon, R., Sun, J.

Funding OrganizationLocationGrant Number
Howard Hughes Medical InstituteUnited States--
American Heart AssociationUnited States17POST32260003

Revision History 

  • Version 1.0: 2017-06-07
    Type: Initial release
  • Version 1.1: 2017-09-13
    Type: Author supporting evidence, Data collection
  • Version 1.2: 2018-10-24
    Type: Data collection, Database references, Other