3KTT

Atomic model of bovine TRiC CCT2(beta) subunit derived from a 4.0 Angstrom cryo-EM map


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.00 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

4.0-A resolution cryo-EM structure of the mammalian chaperonin TRiC/CCT reveals its unique subunit arrangement.

Cong, Y.Baker, M.L.Jakana, J.Woolford, D.Miller, E.J.Reissmann, S.Kumar, R.N.Redding-Johanson, A.M.Batth, T.S.Mukhopadhyay, A.Ludtke, S.J.Frydman, J.Chiu, W.

(2010) Proc Natl Acad Sci U S A 107: 4967-4972

  • DOI: https://doi.org/10.1073/pnas.0913774107
  • Primary Citation of Related Structures:  
    3IYG, 3KTT

  • PubMed Abstract: 

    The essential double-ring eukaryotic chaperonin TRiC/CCT (TCP1-ring complex or chaperonin containing TCP1) assists the folding of approximately 5-10% of the cellular proteome. Many TRiC substrates cannot be folded by other chaperonins from prokaryotes or archaea. These unique folding properties are likely linked to TRiC's unique heterooligomeric subunit organization, whereby each ring consists of eight different paralogous subunits in an arrangement that remains uncertain. Using single particle cryo-EM without imposing symmetry, we determined the mammalian TRiC structure at 4.7-A resolution. This revealed the existence of a 2-fold axis between its two rings resulting in two homotypic subunit interactions across the rings. A subsequent 2-fold symmetrized map yielded a 4.0-A resolution structure that evinces the densities of a large fraction of side chains, loops, and insertions. These features permitted unambiguous identification of all eight individual subunits, despite their sequence similarity. Independent biochemical near-neighbor analysis supports our cryo-EM derived TRiC subunit arrangement. We obtained a Calpha backbone model for each subunit from an initial homology model refined against the cryo-EM density. A subsequently optimized atomic model for a subunit showed approximately 95% of the main chain dihedral angles in the allowable regions of the Ramachandran plot. The determination of the TRiC subunit arrangement opens the way to understand its unique function and mechanism. In particular, an unevenly distributed positively charged wall lining the closed folding chamber of TRiC differs strikingly from that of prokaryotic and archaeal chaperonins. These interior surface chemical properties likely play an important role in TRiC's cellular substrate specificity.


  • Organizational Affiliation

    National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemsitry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
T-complex protein 1 subunit betaA [auth B]513Bos taurusMutation(s): 0 
UniProt
Find proteins for Q3ZBH0 (Bos taurus)
Explore Q3ZBH0 
Go to UniProtKB:  Q3ZBH0
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ3ZBH0
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4.00 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
RECONSTRUCTIONEMAN

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2010-03-16
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2018-07-18
    Changes: Data collection
  • Version 1.3: 2024-02-21
    Changes: Data collection, Database references