3J1C

Cryo-EM structure of 9-fold symmetric rATcpn-alpha in apo state

Summary for 3J1C

• Entry DOI: 10.2210/pdb3j1c/pdb
• Related: 3J1B 3J1D 3J1E 3J1F 3J1G 3J1H 3J1I 3J1J 3J1K 3J1L
• EMDB information: 5392
• Descriptor: Chaperonin alpha subunit (1 entity in total)
• Functional Keywords: group ii chaperonin, chaperone
• Biological source: Acidianus tengchongensis
• Total number of polymer chains: 18
• Total formula weight: 1084847.13

Authors

Zhang, K.,Wang, L.,Liu, Y.X.,Wang, X.,Gao, B.,Hu, Z.J.,Ji, G.,Chan, K.Y.,Schulten, K.,Dong, Z.Y.,Sun, F. (deposition date: 2012-02-06, release date: 2013-08-07, Last modification date: 2024-02-21)

Primary citation

Zhang, K.,Wang, L.,Liu, Y.,Chan, K.Y.,Pang, X.,Schulten, K.,Dong, Z.,Sun, F.
Flexible interwoven termini determine the thermal stability of thermosomes.
Protein Cell, 4:432-444, 2013

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.

PubMed: 23709365
DOI: 10.1007/s13238-013-3026-9

Experimental method

ELECTRON MICROSCOPY (9.1 Å)