Download MendeleyStructural and mechanistic characterization of an archaeal-like chaperonin from a thermophilic bacterium
An, Y.J., Rowland, S.E., Na, J.H., Spigolon, D., Hong, S.K., Yoon, Y.J., Lee, J.H., Robb, F.T., Cha, S.S.(2017) Nat Commun 8: 827-827
- PubMed: 29018216
- DOI: https://doi.org/10.1038/s41467-017-00980-z
- Primary Citation of Related Structures:
5X9U, 5X9V - PubMed Abstract:
The chaperonins (CPNs) are megadalton sized hollow complexes with two cavities that open and close to encapsulate non-native proteins. CPNs are assigned to two sequence-related groups that have distinct allosteric mechanisms. In Group I CPNs a detachable co-chaperone, GroES, closes the chambers whereas in Group II a built-in lid closes the chambers. Group I CPNs have a bacterial ancestry, whereas Group II CPNs are archaeal in origin. Here we describe open and closed crystal structures representing a new phylogenetic branch of CPNs. These Group III CPNs are divergent in sequence and structure from extant CPNs, but are closed by a built-in lid like Group II CPNs. A nucleotide-sensing loop, present in both Group I and Group II CPNs, is notably absent. We identified inter-ring pivot joints that articulate during ring closure. These Group III CPNs likely represent a relic from the ancestral CPN that formed distinct bacterial and archaeal branches.Chaperonins (CPNs) are ATP-dependent protein-folding machines. Here the authors present the open and closed crystal structures of a Group III CPN from the thermophilic bacterium Carboxydothermus hydrogenoformans, discuss its mechanism and structurally compare it with Group I and II CPNs.
Organizational Affiliation:
Marine Biotechnology Research Center, Korea Institute of Ocean Science and Technology, Ansan, 15627, Republic of Korea.
