3KXD

Crystal structure of the mthk rck in complex with cadmium


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.184 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structure of the MthK RCK in complex with cadmium.

Dvir, H.Valera, E.Choe, S.

(2010) J.Struct.Biol. 171: 231-237

  • DOI: 10.1016/j.jsb.2010.03.020

  • PubMed Abstract: 
  • RCK is a cytoplasmic regulatory domain of calcium-gated potassium channels. Binding of Ca(2+) by RCK leads to channel activation through a series of yet unknown conformational changes. Structures of the K(+) channel, MthK, and its cytoplasmic RCK dom ...

    RCK is a cytoplasmic regulatory domain of calcium-gated potassium channels. Binding of Ca(2+) by RCK leads to channel activation through a series of yet unknown conformational changes. Structures of the K(+) channel, MthK, and its cytoplasmic RCK domain revealed two binding sites for Ca(2+) per dimer. We determined the crystal structure of RCK in complex with Cd(2+) at 2.2A resolution. Cd(2+) activates MthK more efficiently, and binds at the same binding sites for Ca(2+) but with reduced coordination number. Two additional binding sites for Cd(2+) are found per dimer; one on the main Rossman-fold lobe, and the other on the small lobe of RCK. Using patch-clamp experiments, we demonstrate that Cd(2+) binding to these novel sites enhances activation by Cd(2+) and not by Ca(2+). The structure reveals a large negatively charged surface patch in the proximity of the Ca(2+)/Cd(2+) binding sites, charge neutralization of which appears to promote the channel open state.


    Organizational Affiliation

    Structural Biology Laboratory, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Calcium-gated potassium channel mthK
A, B
224Methanothermobacter thermautotrophicus (strain ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H)Mutation(s): 0 
Gene Names: mthK
Find proteins for O27564 (Methanothermobacter thermautotrophicus (strain ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H))
Go to UniProtKB:  O27564
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CD
Query on CD

Download SDF File 
Download CCD File 
A, B
CADMIUM ION
Cd
WLZRMCYVCSSEQC-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.184 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 58.022α = 90.00
b = 38.293β = 95.10
c = 96.634γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALAdata scaling
REFMACphasing
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2009-12-02 
  • Released Date: 2010-04-21 
  • Deposition Author(s): Dvir, H., Choe, S.

Revision History 

  • Version 1.0: 2010-04-21
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance