Mechanism of lid closure in the eukaryotic chaperonin TRiC/CCT
Booth, C.R. and Meyer, A.S. and Cong, Y. and Topf, Maya and Sali, A. and Ludtke, Steven J. and Chiu, W. and Frydman, J. (2008) Mechanism of lid closure in the eukaryotic chaperonin TRiC/CCT. Nature Structural and Molecular Biology 15 (7), pp. 746-753. ISSN 1545-9993.
All chaperonins mediate ATP-dependent polypeptide folding by confining substrates within a central chamber. Intriguingly, the eukaryotic chaperonin TRiC (also called CCT) uses a built-in lid to close the chamber, whereas prokaryotic chaperonins use a detachable lid. Here we determine the mechanism of lid closure in TRiC using single-particle cryo-EM and comparative protein modeling. Comparison of TRiC in its open, nucleotide-free, and closed, nucleotide-induced states reveals that the interdomain motions leading to lid closure in TRiC are radically different from those of prokaryotic chaperonins, despite their overall structural similarity. We propose that domain movements in TRiC are coordinated through unique interdomain contacts within each subunit and, further, these contacts are absent in prokaryotic chaperonins. Our findings show how different mechanical switches can evolve from a common structural framework through modification of allosteric networks.
|School:||Birkbeck Schools and Departments > School of Science > Biological Sciences|
|Research Centre:||Bioinformatics, Bloomsbury Centre for, Structural Molecular Biology, Institute of (ISMB)|
|Date Deposited:||04 Aug 2010 14:09|
|Last Modified:||07 Dec 2016 15:02|
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