3GJ9

crystal structure of TIP-1 in complex with c-terminal of Kir2.3


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.247 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Molecular mechanism of inward rectifier potassium channel 2.3 regulation by tax-interacting protein-1

Yan, X.Zhou, H.Zhang, J.Shi, C.Xie, X.Wu, Y.Tian, C.Shen, Y.Long, J.

(2009) J.Mol.Biol. 392: 967-976

  • DOI: 10.1016/j.jmb.2009.07.060

  • PubMed Abstract: 
  • Inwardly rectifying potassium channel 2.3 (Kir2.3) is specifically targeted on the basolateral membranes of epithelial and neuronal cells, and it thus plays an important role in maintaining potassium homeostasis. Tax-interacting protein-1 (TIP-1), an ...

    Inwardly rectifying potassium channel 2.3 (Kir2.3) is specifically targeted on the basolateral membranes of epithelial and neuronal cells, and it thus plays an important role in maintaining potassium homeostasis. Tax-interacting protein-1 (TIP-1), an atypical PDZ-domain-containing protein, binds to Kir2.3 with a high affinity, causing the intracellular accumulation of Kir2.3 in cultured epithelial cells. However, the molecular basis of the TIP-1/Kir2.3 interaction is still poorly understood. Here, we present the crystal structure of TIP-1 in complex with the C-terminal Kir2.3-peptide (residues 436-445) to reveal the molecular details of the interaction between them. Moreover, isothermal titration calorimetry experiments show that the C-terminal Kir2.3-peptide binds much more strongly to TIP-1 than to mammalian Lin-7, indicating that TIP-1 can compete with mammalian Lin-7 to uncouple Kir2.3 from its basolateral membrane anchoring complex. We further show that the phosphorylation/dephosphorylation of Ser443 within the C-terminal Kir2.3 PDZ-binding motif RRESAI dynamically regulates the Kir2.3/TIP-1 association in heterologous HEK293T cells. These data suggest that TIP-1 may act as an important regulator for the endocytic pathway of Kir2.3.


    Organizational Affiliation

    Tianjin Key Laboratory of Protein Science, College of Life Science, Nankai University, Tianjin 300071, China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Tax1-binding protein 3
A, B
124Homo sapiensGene Names: TAX1BP3 (TIP1)
Find proteins for O14907 (Homo sapiens)
Go to Gene View: TAX1BP3
Go to UniProtKB:  O14907
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
C-terminal peptide from Inward rectifier potassium channel 4
C, D
10Homo sapiensGene Names: KCNJ4 (IRK3)
Find proteins for P48050 (Homo sapiens)
Go to Gene View: KCNJ4
Go to UniProtKB:  P48050
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

Download SDF File 
Download CCD File 
A, B
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.247 
  • Space Group: P 43 2 2
Unit Cell:
Length (Å)Angle (°)
a = 86.457α = 90.00
b = 86.457β = 90.00
c = 101.517γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
HKL-2000data collection
CNSrefinement
HKL-2000data reduction
PHASESphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2009-03-08 
  • Released Date: 2009-12-15 
  • Deposition Author(s): Shen, Y.

Revision History 

  • Version 1.0: 2009-12-15
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance