2BOL

CRYSTAL STRUCTURE AND ASSEMBLY OF TSP36, A METAZOAN SMALL HEAT SHOCK PROTEIN


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.207 

wwPDB Validation   3D Report Full Report


This is version 1.4 of the entry. See complete history


Literature

Wrapping the Alpha-Crystallin Domain Fold in a Chaperone Assembly.

Stamler, R.J.Kappe, G.Boelens, W.C.Slingsby, C.

(2005) J Mol Biol 353: 68

  • DOI: https://doi.org/10.1016/j.jmb.2005.08.025
  • Primary Citation of Related Structures:  
    2BOL

  • PubMed Abstract: 

    Small heat shock proteins (sHsps) are oligomers that perform a protective function by binding denatured proteins. Although ubiquitous, they are of variable sequence except for a C-terminal approximately 90-residue "alpha-crystallin domain". Unlike larger stress response chaperones, sHsps are ATP-independent and generally form polydisperse assemblies. One proposed mechanism of action involves these assemblies breaking into smaller subunits in response to stress, before binding unfolding substrate and reforming into larger complexes. Two previously solved non-metazoan sHsp multimers are built from dimers formed by domain swapping between the alpha-crystallin domains, adding to evidence that the smaller subunits are dimers. Here, the 2.5A resolution structure of an sHsp from the parasitic flatworm Taenia saginata Tsp36, the first metazoan crystal structure, shows a new mode of dimerization involving N-terminal regions, which differs from that seen for non-metazoan sHsps. Sequence differences in the alpha-crystallin domains between metazoans and non-metazoans are critical to the different mechanism of dimerization, suggesting that some structural features seen for Tsp36 may be generalized to other metazoan sHsps. The structure also indicates scope for flexible assembly of subunits, supporting the proposed process of oligomer breakdown, substrate binding and reassembly as the chaperone mechanism. It further shows how sHsps can bind coil and secondary structural elements by wrapping them around the alpha-crystallin domain. The structure also illustrates possible roles for conserved residues associated with disease, and suggests a mechanism for the sHsp-related pathogenicity of some flatworm infections. Tsp36, like other flatworm sHsps, possesses two divergent sHsp repeats per monomer. Together with the two previously solved structures, a total of four alpha-crystallin domain structures are now available, giving a better definition of domain boundaries for sHsps.


  • Organizational Affiliation

    Department of Crystallography, Birkbeck College, Malet Street, London WC1E 7HX, UK.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
SMALL HEAT SHOCK PROTEIN
A, B
314Taenia saginataMutation(s): 0 
UniProt
Find proteins for Q7YZT0 (Taenia saginata)
Explore Q7YZT0 
Go to UniProtKB:  Q7YZT0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ7YZT0
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.207 
  • R-Value Observed: 0.207 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.59α = 90
b = 102.05β = 90
c = 139.48γ = 90
Software Package:
Software NamePurpose
CNSrefinement
MOSFLMdata reduction
SCALAdata scaling
autoSHARPphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-09-23
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2019-05-08
    Changes: Data collection, Experimental preparation, Other
  • Version 1.4: 2024-05-08
    Changes: Data collection, Database references, Other