3IYG

Ca model of bovine TRiC/CCT derived from a 4.0 Angstrom cryo-EM map


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report


This is version 1.1 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.USA 107: 4967-4972

  • DOI: 10.1073/pnas.0913774107
  • Primary Citation of Related Structures:  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 prokaryote ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
T-complex protein 1 subunit theta
Q
512Bos taurusGene Names: CCT8
Find proteins for Q3ZCI9 (Bos taurus)
Go to Gene View: CCT8
Go to UniProtKB:  Q3ZCI9
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
T-complex protein 1 subunit gamma
G
515Bos taurusGene Names: CCT3
Find proteins for Q3T0K2 (Bos taurus)
Go to Gene View: CCT3
Go to UniProtKB:  Q3T0K2
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
T-complex protein 1 subunit zeta
Z
517Bos taurusGene Names: CCT6A
Find proteins for Q3MHL7 (Bos taurus)
Go to Gene View: CCT6A
Go to UniProtKB:  Q3MHL7
Entity ID: 4
MoleculeChainsSequence LengthOrganismDetails
T-complex protein 1 subunit delta
D
518Bos taurusGene Names: CCT4
Find proteins for Q2T9X2 (Bos taurus)
Go to Gene View: CCT4
Go to UniProtKB:  Q2T9X2
Entity ID: 5
MoleculeChainsSequence LengthOrganismDetails
T-complex protein 1 subunit beta
B
513Bos taurusGene Names: CCT2
Find proteins for Q3ZBH0 (Bos taurus)
Go to Gene View: CCT2
Go to UniProtKB:  Q3ZBH0
Entity ID: 6
MoleculeChainsSequence LengthOrganismDetails
T-complex protein 1 subunit
E
515N/AN/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 7
MoleculeChainsSequence LengthOrganismDetails
T-complex protein 1 subunit alpha
A
529Bos taurusGene Names: TCP1 (CCT1)
Find proteins for Q32L40 (Bos taurus)
Go to Gene View: TCP1
Go to UniProtKB:  Q32L40
Entity ID: 8
MoleculeChainsSequence LengthOrganismDetails
T-complex protein 1 subunit eta
H
515Bos taurusGene Names: CCT7
Find proteins for Q2NKZ1 (Bos taurus)
Go to Gene View: CCT7
Go to UniProtKB:  Q2NKZ1
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-03-16
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance