5X9V

Crystal structure of group III chaperonin in the Closed state

Summary for 5X9V

• Entry DOI: 10.2210/pdb5x9v/pdb
• Related: 5X9U
• Descriptor: Thermosome, alpha subunit, PHOSPHOAMINOPHOSPHONIC ACID-ADENYLATE ESTER, MAGNESIUM ION (3 entities in total)
• Functional Keywords: group iii, archaeal-like bacterial chaperonin, closed states, pivot joints, ancestral cpn60, chaperone
• Biological source: Carboxydothermus hydrogenoformans Z-2901
• Total number of polymer chains: 4
• Total formula weight: 228881.99

Authors

An, Y.J.,Cha, S.S. (deposition date: 2017-03-09, release date: 2017-10-25, Last modification date: 2023-11-22)

Primary citation

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.
Structural and mechanistic characterization of an archaeal-like chaperonin from a thermophilic bacterium
Nat Commun, 8:827-827, 2017

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.

PubMed: 29018216
DOI: 10.1038/s41467-017-00980-z

Experimental method

X-RAY DIFFRACTION (3.003 Å)