Cryo-EM structure of 8-fold symmetric rATcpn-alpha in apo state

Experimental Data Snapshot

  • Resolution: 4.90 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

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Flexible interwoven termini determine the thermal stability of thermosomes.

Zhang, K.Wang, L.Liu, Y.Chan, K.Y.Pang, X.Schulten, K.Dong, Z.Sun, F.

(2013) Protein Cell 4: 432-444

  • DOI: https://doi.org/10.1007/s13238-013-3026-9
  • Primary Citation of Related Structures:  
    3J1B, 3J1C, 3J1E, 3J1F

  • PubMed Abstract: 

    Group II chaperonins, which assemble as double-ring complexes, assist in the refolding of nascent peptides or denatured proteins in an ATP-dependent manner. The molecular mechanism of group II chaperonin assembly and thermal stability is yet to be elucidated. Here, we selected the group II chaperonins (cpn-α and cpn-β), also called thermosomes, from Acidianus tengchongensis and investigated their assembly and thermal stability. We found that the binding of ATP or its analogs contributed to the successful assembly of thermosomes and enhanced their thermal stabilities. Cpn-β is more thermally stable than cpn-α, while the thermal stability of the hetero thermosome cpn-αβ is intermediate. Cryo-electron microscopy reconstructions of cpn-α and cpn-β revealed the interwoven densities of their non-conserved flexible N/C-termini around the equatorial planes. The deletion or swapping of their termini and pH-dependent thermal stability assays revealed the key role of the termini electrostatic interactions in the assembly and thermal stability of the thermosomes.

  • Organizational Affiliation

    National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Chaperonin alpha subunit
A, B, C, D, E
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P
563Acidianus tengchongensisMutation(s): 0 
Find proteins for Q877H0 (Acidianus tengchongensis)
Explore Q877H0 
Go to UniProtKB:  Q877H0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ877H0
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 4.90 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-08-07
    Type: Initial release
  • Version 1.1: 2018-07-18
    Changes: Data collection
  • Version 1.2: 2024-02-21
    Changes: Data collection, Database references, Refinement description