3SYA

Crystal structure of the G protein-gated inward rectifier K+ channel GIRK2 (Kir3.2) in complex with sodium and PIP2

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.98 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.240 
  • R-Value Observed: 0.242 

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Literature

Crystal Structure of the Mammalian GIRK2 K(+) Channel and Gating Regulation by G Proteins, PIP(2), and Sodium.

Whorton, M.R., Mackinnon, R.

(2011) Cell 147: 199-208

  • DOI: 10.1016/j.cell.2011.07.046
  • Primary Citation of Related Structures:  
    3SYQ, 3SYO, 3SYP, 3SYA, 3SYC

  • PubMed Abstract: 

    • G protein-gated K(+) channels (Kir3.1-Kir3.4) control electrical excitability in many different cells. Among their functions relevant to human physiology and disease, they regulate the heart rate and govern a wide range of neuronal activities. Here, ...

    G protein-gated K(+) channels (Kir3.1-Kir3.4) control electrical excitability in many different cells. Among their functions relevant to human physiology and disease, they regulate the heart rate and govern a wide range of neuronal activities. Here, we present the first crystal structures of a G protein-gated K(+) channel. By comparing the wild-type structure to that of a constitutively active mutant, we identify a global conformational change through which G proteins could open a G loop gate in the cytoplasmic domain. The structures of both channels in the absence and presence of PIP(2) suggest that G proteins open only the G loop gate in the absence of PIP(2), but in the presence of PIP(2) the G loop gate and a second inner helix gate become coupled, so that both gates open. We also identify a strategically located Na(+) ion-binding site, which would allow intracellular Na(+) to modulate GIRK channel activity. These data provide a structural basis for understanding multiligand regulation of GIRK channel gating.

    Organizational Affiliation: 

    Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, New York, NY 10065, USA.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
G protein-activated inward rectifier potassium channel 2A340Mus musculusMutation(s): 0 
Gene Names: Girk2, Kcnj6, Kcnj7, W
Membrane protein
Mpstruc		Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL		Sub Group: 
Channels: Potassium, Sodium, & Proton Ion-Selective		Protein: 
GIRK2 (Kir3.2) G-protein-gated K+ channel
Find proteins for P48542 (Mus musculus)
Explore P48542 
Go to UniProtKB:  P48542
NIH Common Fund Data Resources
IMPC  MGI:104781
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PIO
Query on PIO
Download Ideal Coordinates CCD File 
A
[(2R)-2-octanoyloxy-3-[oxidanyl-[(1R,2R,3S,4R,5R,6S)-2,3,6-tris(oxidanyl)-4,5-diphosphonooxy-cyclohexyl]oxy-phosphoryl]oxy-propyl] octanoate
C25 H49 O19 P3
XLNCEHRXXWQMPK-MJUMVPIBSA-N		 Ligand Interaction
K
Query on K
Download Ideal Coordinates CCD File 
A
POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N		 Ligand Interaction
NA
Query on NA
Download Ideal Coordinates CCD File 
A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N		 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.98 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.240 
  • R-Value Observed: 0.242 
  • Space Group: P 4 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 85.851α = 90
b = 85.851β = 90
c = 177.862γ = 90
Software Package:
Software NamePurpose
SCALEPACKdata scaling
REFMACrefinement
PDB_EXTRACTdata extraction
CBASSdata collection
DENZOdata reduction
MOLREPphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-10-12
    Type: Initial release