3STZ

KcsA potassium channel mutant Y82C with nitroxide spin label


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.285 
  • R-Value Work: 0.246 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Mechanism of Cd(2+) Coordination during Slow Inactivation in Potassium Channels.

Raghuraman, H.Cordero-Morales, J.F.Jogini, V.Pan, A.C.Kollewe, A.Roux, B.Perozo, E.

(2012) Structure 20: 1332-1342

  • DOI: 10.1016/j.str.2012.03.027
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • In K+ channels, rearrangements of the pore outer vestibule have been associated with C-type inactivation gating. Paradoxically, the crystal structure of Open/C-type inactivated KcsA suggests these movements to be modest in magnitude. In this study, w ...

    In K+ channels, rearrangements of the pore outer vestibule have been associated with C-type inactivation gating. Paradoxically, the crystal structure of Open/C-type inactivated KcsA suggests these movements to be modest in magnitude. In this study, we show that under physiological conditions, the KcsA outer vestibule undergoes relatively large dynamic rearrangements upon inactivation. External Cd2+ enhances the rate of C-type inactivation in an cysteine mutant (Y82C) via metal-bridge formation. This effect is not present in a non-inactivating mutant (E71A/Y82C). Tandem dimer and tandem tetramer constructs of equivalent cysteine mutants in KcsA and Shaker K+ channels demonstrate that these Cd2+ metal bridges are formed only between adjacent subunits. This is well supported by molecular dynamics simulations. Based on the crystal structure of Cd2+ -bound Y82C-KcsA in the closed state, together with electron paramagnetic resonance distance measurements in the KcsA outer vestibule, we suggest that subunits must dynamically come in close proximity as the channels undergo inactivation.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, IL, USA.




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
Voltage-gated potassium channel
C
102Streptomyces lividansMutation(s): 1 
Gene 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
Small Molecules
Ligands 2 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
MTN
Query on MTN

Download SDF File 
Download CCD File 
C
S-[(1-oxyl-2,2,5,5-tetramethyl-2,5-dihydro-1H-pyrrol-3-yl)methyl] methanesulfonothioate
MTSL
C10 H18 N O3 S2
MXZPGYFBZHBAQM-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.285 
  • R-Value Work: 0.246 
  • Space Group: I 4
Unit Cell:
Length (Å)Angle (°)
a = 155.732α = 90.00
b = 155.732β = 90.00
c = 76.098γ = 90.00
Software Package:
Software NamePurpose
CNSphasing
HKL-2000data reduction
CNSrefinement
ADSCdata collection
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-04-18
    Type: Initial release
  • Version 1.1: 2012-10-03
    Type: Database references