2FY8

Crystal structure of MthK rck domain in its ligand-free gating-ring form


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.79 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.213 

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This is version 1.3 of the entry. See complete history


Literature

Crystal Structures of a Ligand-free MthK Gating Ring: Insights into the Ligand Gating Mechanism of K(+) Channels.

Ye, S.Li, Y.Chen, L.Jiang, Y.

(2006) Cell 126: 1161-1173

  • DOI: 10.1016/j.cell.2006.08.029
  • Primary Citation of Related Structures:  
    2FY8

  • PubMed Abstract: 
  • MthK is a prokaryotic Ca(2+)-gated K(+) channel that, like other ligand-gated channels, converts the chemical energy of ligand binding to the mechanical force of channel opening. The channel's eight ligand-binding domains, the RCK domains, form an octameric gating ring in which Ca(2+) binding induces conformational changes that open the channel ...

    MthK is a prokaryotic Ca(2+)-gated K(+) channel that, like other ligand-gated channels, converts the chemical energy of ligand binding to the mechanical force of channel opening. The channel's eight ligand-binding domains, the RCK domains, form an octameric gating ring in which Ca(2+) binding induces conformational changes that open the channel. Here we present the crystal structures of the MthK gating ring in closed and partially open states at 2.8 A, both obtained from the same crystal grown in the absence of Ca(2+). Furthermore, our biochemical and electrophysiological analyses demonstrate that MthK is regulated by both Ca(2+) and pH. Ca(2+) regulates the channel by changing the equilibrium of the gating ring between closed and open states, while pH regulates channel gating by affecting gating-ring stability. Our findings, along with the previously determined open MthK structure, allow us to elucidate the ligand gating mechanism of RCK-regulated K(+) channels.


    Organizational Affiliation

    Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Calcium-gated potassium channel mthK
A, B, C, D, E, F, G, H
A, B, C, D, E, F, G, H
230Methanothermobacter thermautotrophicusMutation(s): 1 
Gene Names: mthK
UniProt
Find proteins for O27564 (Methanothermobacter thermautotrophicus (strain ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H))
Explore O27564 
Go to UniProtKB:  O27564
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO27564
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.79 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.213 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 174.141α = 90
b = 180.965β = 90
c = 252.748γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
XTALVIEWrefinement

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-09-05
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.3: 2021-10-20
    Changes: Database references