3AGW

Crystal Structure of the Cytoplasmic Domain of G-Protein-Gated Inward Rectifier Potassium Channel Kir3.2 in the absence of Na+


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.198 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

A structural determinant for the control of PIP2 sensitivity in G protein-gated inward rectifier K+ channels

Inanobe, A.Nakagawa, A.Matsuura, T.Kurachi, Y.

(2010) J.Biol.Chem. 285: 38517-38523

  • DOI: 10.1074/jbc.M110.161703

  • PubMed Abstract: 
  • Inward rectifier K(+) (Kir) channels are activated by phosphatidylinositol-(4,5)-bisphosphate (PIP(2)), but G protein-gated Kir (K(G)) channels further require either G protein βγ subunits (Gβγ) or intracellular Na(+) for their activation. To reveal ...

    Inward rectifier K(+) (Kir) channels are activated by phosphatidylinositol-(4,5)-bisphosphate (PIP(2)), but G protein-gated Kir (K(G)) channels further require either G protein βγ subunits (Gβγ) or intracellular Na(+) for their activation. To reveal the mechanism(s) underlying this regulation, we compared the crystal structures of the cytoplasmic domain of K(G) channel subunit Kir3.2 obtained in the presence and the absence of Na(+). The Na(+)-free Kir3.2, but not the Na(+)-plus Kir3.2, possessed an ionic bond connecting the N terminus and the CD loop of the C terminus. Functional analyses revealed that the ionic bond between His-69 on the N terminus and Asp-228 on the CD loop, which are known to be critically involved in Gβγ- and Na(+)-dependent activation, lowered PIP(2) sensitivity. The conservation of these residues within the K(G) channel family indicates that the ionic bond is a character that maintains the channels in a closed state by controlling the PIP(2) sensitivity.


    Organizational Affiliation

    Department of Pharmacology, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan. inanobe@pharma2.med.osaka-u.ac.jp




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
G protein-activated inward rectifier potassium channel 2
A
208Mus musculusMutation(s): 0 
Gene Names: Kcnj6 (Girk2, Kcnj7, W)
Find proteins for P48542 (Mus musculus)
Go to UniProtKB:  P48542
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MG
Query on MG

Download SDF File 
Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
EOH
Query on EOH

Download SDF File 
Download CCD File 
A
ETHANOL
C2 H6 O
LFQSCWFLJHTTHZ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.198 
  • Space Group: I 4 2 2
Unit Cell:
Length (Å)Angle (°)
a = 81.943α = 90.00
b = 81.943β = 90.00
c = 172.769γ = 90.00
Software Package:
Software NamePurpose
MOLREPphasing
HKL-2000data reduction
REFMACrefinement
HKL-2000data scaling
HKL-2000data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2010-04-08 
  • Released Date: 2010-09-29 
  • Deposition Author(s): Inanobe, A.

Revision History 

  • Version 1.0: 2010-09-29
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2014-01-29
    Type: Database references
  • Version 1.3: 2017-08-16
    Type: Refinement description, Source and taxonomy