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: 2.20 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.200 

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
  • Primary Citation of Related Structures:  
    3AGW

  • 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:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
G protein-activated inward rectifier potassium channel 2A208Mus musculusMutation(s): 0 
Gene Names: Kcnj6
Find proteins for P48542 (Mus musculus)
Explore P48542 
Go to UniProtKB:  P48542
NIH Common Fund Data Resources
IMPC  MGI:104781
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
EOH
Query on EOH

Download Ideal Coordinates CCD File 
A
ETHANOL
C2 H6 O
LFQSCWFLJHTTHZ-UHFFFAOYSA-N
 Ligand Interaction
MG
Query on MG

Download Ideal Coordinates CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.198 
  • R-Value Observed: 0.200 
  • Space Group: I 4 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 81.943α = 90
b = 81.943β = 90
c = 172.769γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
MOLREPphasing
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



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
    Changes: Version format compliance
  • Version 1.2: 2014-01-29
    Changes: Database references
  • Version 1.3: 2017-08-16
    Changes: Refinement description, Source and taxonomy