
T-complex protein Ring Complex (TRiC), otherwise known as Chaperonin Containing TCP-1 (CCT), is a
multiprotein complex and the
chaperonin of eukaryotic cells. Like the bacterial
GroEL, the TRiC complex aids in the folding of ~10% of the proteome, and
actin
Actin is a protein family, family of Globular protein, globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in myofibril, muscle fibrils. It is found in essentially all Eukaryote, eukaryotic cel ...
and
tubulin are some of its best known substrates.
TRiC is an example of a
biological machine that folds substrates within the central cavity of its barrel-like assembly using the energy from
ATP
ATP may refer to:
Companies and organizations
* Association of Tennis Professionals, men's professional tennis governing body
* American Technical Publishers, employee-owned publishing company
* ', a Danish pension
* Armenia Tree Project, non ...
hydrolysis.
Subunits
The human TRiC complex is formed by two rings containing 8 similar but non-identical subunits, each with molecular weights of ~60 kDa. The two rings are stacked in an asymmetrical fashion, forming a barrel-like structure with a molecular weight of ~1 MDa.
Molecular weight of human subunits.
Counterclockwise from the exterior, each ring is made of the subunits in the following order: 6-8-7-5-2-4-1-3.
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Evolution
The CCT evolved from the archaeal thermosome ~2Gya, with the two subunits diversifying into multiple units. The CCT changed from having one type of subunit, to having two, three, five, and finally eight types.
See also
* Chaperone
* Chaperonin
* Heat shock protein
Notes
References
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Molecular biology
Gene expression
Protein complexes