TY  - JOUR
AU  - Zhang, J.
AU  - Baker, M.L.
AU  - Schröder, G.F.
AU  - Douglas, N.R.
AU  - Reissmann, S.
AU  - Jakana, J.
AU  - Dougherty, M.
AU  - Fu, C.J.
AU  - Levitt, M.
AU  - Ludtke, S.J.
AU  - Frydman, J.
AU  - Chiu, W.
TI  - Mechanism of folding chamber closure in a group II chaperonin
JO  - Nature 
VL  - 463
SN  - 0028-0836
CY  - London [u.a.]
PB  - Nature Publising Group
M1  - PreJuSER-8698
SP  - 379 - 383
PY  - 2010
N1  - We acknowledge the support of grants from the National Institutes of Health through the Nanomedicine Development Center Roadmap Initiative, Biomedical Technology Research Center for Structural Biology in National Center for Research Resources, Nanobiology Training Fellowship administered by the Keck Center of the Gulf Coast Consortia and the National Science Foundation.
AB  - Group II chaperonins are essential mediators of cellular protein folding in eukaryotes and archaea. These oligomeric protein machines, approximately 1 megadalton, consist of two back-to-back rings encompassing a central cavity that accommodates polypeptide substrates. Chaperonin-mediated protein folding is critically dependent on the closure of a built-in lid, which is triggered by ATP hydrolysis. The structural rearrangements and molecular events leading to lid closure are still unknown. Here we report four single particle cryo-electron microscopy (cryo-EM) structures of Mm-cpn, an archaeal group II chaperonin, in the nucleotide-free (open) and nucleotide-induced (closed) states. The 4.3 A resolution of the closed conformation allowed building of the first ever atomic model directly from the single particle cryo-EM density map, in which we were able to visualize the nucleotide and more than 70% of the side chains. The model of the open conformation was obtained by using the deformable elastic network modelling with the 8 A resolution open-state cryo-EM density restraints. Together, the open and closed structures show how local conformational changes triggered by ATP hydrolysis lead to an alteration of intersubunit contacts within and across the rings, ultimately causing a rocking motion that closes the ring. Our analyses show that there is an intricate and unforeseen set of interactions controlling allosteric communication and inter-ring signalling, driving the conformational cycle of group II chaperonins. Beyond this, we anticipate that our methodology of combining single particle cryo-EM and computational modelling will become a powerful tool in the determination of atomic details involved in the dynamic processes of macromolecular machines in solution.
KW  - Adenosine Triphosphate: chemistry
KW  - Adenosine Triphosphate: metabolism
KW  - Adenosine Triphosphate: pharmacology
KW  - Allosteric Regulation
KW  - Binding Sites
KW  - Cryoelectron Microscopy
KW  - Group II Chaperonins: chemistry
KW  - Group II Chaperonins: metabolism
KW  - Group II Chaperonins: ultrastructure
KW  - Hydrolysis: drug effects
KW  - Methanococcus: chemistry
KW  - Models, Molecular
KW  - Protein Binding
KW  - Protein Conformation: drug effects
KW  - Protein Folding
KW  - Protein Subunits: chemistry
KW  - Protein Subunits: metabolism
KW  - Structure-Activity Relationship
KW  - Protein Subunits (NLM Chemicals)
KW  - Adenosine Triphosphate (NLM Chemicals)
KW  - Group II Chaperonins (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:20090755
C2  - pmc:PMC2834796
UR  - <Go to ISI:>//WOS:000273748100049
DO  - DOI:10.1038/nature08701
UR  - https://juser.fz-juelich.de/record/8698
ER  -