4a13

model refined against symmetry-free cryo-EM map of TRiC-ADPmodel refined against symmetry-free cryo-EM map of TRiC-ADP

4a13, resolution 11.30Å Show:Asymmetric Unit Biological Assembly Structural highlights 4a13 is a 16 chain structure with sequence from Bos taurus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 11.3Å Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function TCPB_BOVIN Molecular chaperone; assists the folding of proteins upon ATP hydrolysis. As part of the BBS/CCT complex may play a role in the assembly of BBSome, a complex involved in ciliogenesis regulating transports vesicles to the cilia. Known to play a role, in vitro, in the folding of actin and tubulin (By similarity). Publication Abstract from PubMed 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. Symmetry-free cryo-EM structures of the chaperonin TRiC along its ATPase-driven conformational cycle.,Cong Y, Schroder GF, Meyer AS, Jakana J, Ma B, Dougherty MT, Schmid MF, Reissmann S, Levitt M, Ludtke SL, Frydman J, Chiu W EMBO J. 2011 Nov 1;31(3):720-30. doi: 10.1038/emboj.2011.366. PMID:22045336 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Chaperonin 3D structures