4A0W

model built against symmetry-free cryo-EM map of TRiC-ADP-AlFx

Summary for 4A0W

• Entry DOI: 10.2210/pdb4a0w/pdb
• Related: 4A0O 4A0V 4A13
• EMDB information: 1960 1961 1962 1963
• Descriptor: T-COMPLEX PROTEIN 1 SUBUNIT BETA (1 entity in total)
• Functional Keywords: chaperone, chaperonin, protein folding
• Biological source: BOS TAURUS (CATTLE)
• Total number of polymer chains: 16
• Total formula weight: 881715.74

Authors

Cong, Y.,Schroder, G.F.,Meyer, A.S.,Jakana, J.,Ma, B.,Dougherty, M.T.,Schmid, M.F.,Reissmann, S.,Levitt, M.,Ludtke, S.L.,Frydman, J.,Chiu, W. (deposition date: 2011-09-13, release date: 2012-02-15, Last modification date: 2024-05-08)

Primary citation

Cong, Y.,Schroder, G.F.,Meyer, A.S.,Jakana, J.,Ma, B.,Dougherty, M.T.,Schmid, M.F.,Reissmann, S.,Levitt, M.,Ludtke, S.L.,Frydman, J.,Chiu, W.
Symmetry-Free Cryo-Em Structures of the Chaperonin Tric Along its ATPase-Driven Conformational Cycle.
Embo J., 31:720-, 2012

PubMed Abstract: The eukaryotic group II chaperonin TRiC/CCT is a 16-subunit complex with eight distinct but similar subunits arranged in two stacked rings. Substrate folding inside the central chamber is triggered by ATP hydrolysis. We present five cryo-EM structures of TRiC in apo and nucleotide-induced states without imposing symmetry during the 3D reconstruction. These structures reveal the intra- and inter-ring subunit interaction pattern changes during the ATPase cycle. In the apo state, the subunit arrangement in each ring is highly asymmetric, whereas all nucleotide-containing states tend to be more symmetrical. We identify and structurally characterize an one-ring closed intermediate induced by ATP hydrolysis wherein the closed TRiC ring exhibits an observable chamber expansion. This likely represents the physiological substrate folding state. Our structural results suggest mechanisms for inter-ring-negative cooperativity, intra-ring-positive cooperativity, and protein-folding chamber closure of TRiC. Intriguingly, these mechanisms are different from other group I and II chaperonins despite their similar architecture.

PubMed: 22045336
DOI: 10.1038/EMBOJ.2011.366

Experimental method

ELECTRON MICROSCOPY (13.9 Å)