3Q49

Crystal structure of the TPR domain of CHIP complexed with Hsp70-C peptide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.54 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.168 
  • R-Value Observed: 0.170 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Molecular Mechanism of the Negative Regulation of Smad1/5 Protein by Carboxyl Terminus of Hsc70-interacting Protein (CHIP).

Wang, L.Liu, Y.T.Hao, R.Chen, L.Chang, Z.Wang, H.R.Wang, Z.X.Wu, J.W.

(2011) J Biol Chem 286: 15883-15894

  • DOI: https://doi.org/10.1074/jbc.M110.201814
  • Primary Citation of Related Structures:  
    3Q47, 3Q49, 3Q4A

  • PubMed Abstract: 

    The transforming growth factor-β (TGF-β) superfamily of ligands signals along two intracellular pathways, Smad2/3-mediated TGF-β/activin pathway and Smad1/5/8-mediated bone morphogenetic protein pathway. The C terminus of Hsc70-interacting protein (CHIP) serves as an E3 ubiquitin ligase to mediate the degradation of Smad proteins and many other signaling proteins. However, the molecular mechanism for CHIP-mediated down-regulation of TGF-β signaling remains unclear. Here we show that the extreme C-terminal sequence of Smad1 plays an indispensable role in its direct association with the tetratricopeptide repeat (TPR) domain of CHIP. Interestingly, Smad1 undergoes CHIP-mediated polyubiquitination in the absence of molecular chaperones, and phosphorylation of the C-terminal SXS motif of Smad1 enhances the interaction and ubiquitination. We also found that CHIP preferentially binds to Smad1/5 and specifically disrupts the core signaling complex of Smad1/5 and Smad4. We determined the crystal structures of CHIP-TPR in complex with the phosphorylated/pseudophosphorylated Smad1 peptides and with an Hsp70/Hsc70 C-terminal peptide. Structural analyses and subsequent biochemical studies revealed that the distinct CHIP binding affinities of Smad1/5 or Smad2/3 result from the nonconservative hydrophobic residues at R-Smad C termini. Unexpectedly, the C-terminal peptides from Smad1 and Hsp70/Hsc70 bind in the same groove of CHIP-TPR, and heat shock proteins compete with Smad1/5 for CHIP interaction and concomitantly suppress, rather than facilitate, CHIP-mediated Smad ubiquitination. Thus, we conclude that CHIP inhibits the signaling activities of Smad1/5 by recruiting Smad1/5 from the functional R-/Co-Smad complex and further promoting the ubiquitination/degradation of Smad1/5 in a chaperone-independent manner.


  • Organizational Affiliation

    MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing, China.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
STIP1 homology and U box-containing protein 1A [auth B]137Mus musculusMutation(s): 0 
Gene Names: Stub1Chip
EC: 6.3.2 (PDB Primary Data), 2.3.2.27 (UniProt)
UniProt
Find proteins for Q9WUD1 (Mus musculus)
Explore Q9WUD1 
Go to UniProtKB:  Q9WUD1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9WUD1
Sequence Annotations
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  • Reference Sequence

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Hsp70-C peptideB [auth C]8Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P0DMV8 (Homo sapiens)
Explore P0DMV8 
Go to UniProtKB:  P0DMV8
PHAROS:  P0DMV8
GTEx:  ENSG00000204389 
Entity Groups  
UniProt GroupP0DMV8
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.54 Å
  • R-Value Free: 0.206 
  • R-Value Work: 0.168 
  • R-Value Observed: 0.170 
  • Space Group: P 21 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 46.033α = 90
b = 77.967β = 90
c = 37.341γ = 90
Software Package:
Software NamePurpose
MAR345dtbdata collection
PHASERphasing
PHENIXrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-03-16
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2023-11-01
    Changes: Data collection, Database references, Refinement description