Biological Assembly 1  

 3D View: Structure | Electron Density

Global Symmetry: Cyclic - C4  (3D View)
Global Stoichiometry: Homo 4-mer - A4 

Biological assembly 1 assigned by authors and generated by PISA,PQS (software)

Macromolecule Content

• Total Structure Weight: 24.15 kDa 
• Atom Count: 1728 
• Modelled Residue Count: 200 
• Deposited Residue Count: 212 
• Unique protein chains: 1

1U4E

Crystal Structure of Cytoplasmic Domains of GIRK1 channel

• DOI: 10.2210/pdb1U4E/pdb

• Classification: METAL TRANSPORT
• Organism(s): Mus musculus
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2004-07-24 Released: 2005-03-08 
• Deposition Author(s): Pegan, S., Arrabit, C., Zhou, W., Kwiatkowski, W., Slesinger, P.A., Choe, S.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.09 Å
• R-Value Free: 0.235 
• R-Value Work: 0.194 
• R-Value Observed: 0.196 

Literature

Cytoplasmic domain structures of Kir2.1 and Kir3.1 show sites for modulating gating and rectification

Pegan, S., Arrabit, C., Zhou, W., Kwiatkowski, W., Collins, A., Slesinger, P.A., Choe, S.

(2005) Nat Neurosci 8: 279-287

• PubMed: 15723059 
• DOI: 10.1038/nn1411
• Primary Citation of Related Structures:  
  1U4F, 1U4E


• PubMed Abstract: 
  

N- and C-terminal cytoplasmic domains of inwardly rectifying K (Kir) channels control the ion-permeation pathway through diverse interactions with small molecules and protein ligands in the cytoplasm. Two new crystal structures of the cytoplasmic domains of Kir2.1 (Kir2.1(L)) and the G protein-sensitive Kir3.1 (Kir3.1(S)) channels in the absence of PIP(2) show the cytoplasmic ion-permeation pathways occluded by four cytoplasmic loops that form a girdle around the central pore (G-loop). Significant flexibility of the pore-facing G-loop of Kir2.1(L) and Kir3.1(S) suggests a possible role as a diffusion barrier between cytoplasmic and transmembrane pores. Consistent with this, mutations of the G-loop disrupted gating or inward rectification. Structural comparison shows a di-aspartate cluster on the distal end of the cytoplasmic pore of Kir2.1(L) that is important for modulating inward rectification. Taken together, these results suggest the cytoplasmic domains of Kir channels undergo structural changes to modulate gating and inward rectification.

---

Organizational Affiliation: 

Structural Biology, The Salk Institute, La Jolla, California 92037, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
G protein-activated inward rectifier potassium channel 1	A	212	Mus musculus	Mutation(s): 0  Gene Names: Kcnj3, Girk1, Kga
UniProt & NIH Common Fund Data Resources
Find proteins for P63250 (Mus musculus) Explore P63250  Go to UniProtKB:  P63250
IMPC:  MGI:104742

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.09 Å
• R-Value Free: 0.235 
• R-Value Work: 0.194 
• R-Value Observed: 0.196 
• Space Group: P 4 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 76.357	α = 90
b = 76.357	β = 90
c = 92.164	γ = 90

Software Package:

Software Name	Purpose
REFMAC	refinement
HKL-2000	data reduction
SCALEPACK	data scaling
AMoRE	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2004-07-24 
• Released Date: 2005-03-08 
Deposition Author(s): Pegan, S., Arrabit, C., Zhou, W., Kwiatkowski, W., Slesinger, P.A., Choe, S.

Revision History  

• Version 1.0: 2005-03-08
  Type: Initial release
  
• Version 1.1: 2008-04-30
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Derived calculations, Version format compliance
• Version 1.3: 2017-08-23
  Changes: Source and taxonomy