7ylu
yeast TRiC-plp2-substrate complex at S1 TRiC-NPP state
Structural highlights
FunctionTCPB_YEAST Molecular chaperone; assists the folding of proteins upon ATP hydrolysis. Known to play a role, in vitro, in the folding of actin and tubulin. In yeast may play a role in mitotic spindle formation. Publication Abstract from PubMedThe cytoskeletal proteins tubulin and actin are the obligate substrates of TCP-1 ring complex/Chaperonin containing TCP-1 (TRiC/CCT), and their folding involves co-chaperone. Through cryo-electron microscopy analysis, we present a more complete picture of TRiC-assisted tubulin/actin folding along TRiC adenosine triphosphatase cycle, under the coordination of co-chaperone plp2. In the open S1/S2 states, plp2 and tubulin/actin engaged within opposite TRiC chambers. Notably, we captured an unprecedented TRiC-plp2-tubulin complex in the closed S3 state, engaged with a folded full-length beta-tubulin and loaded with a guanosine triphosphate, and a plp2 occupying opposite rings. Another closed S4 state revealed an actin in the intermediate folding state and a plp2. Accompanying TRiC ring closure, plp2 translocation could coordinate substrate translocation on the CCT6 hemisphere, facilitating substrate stabilization and folding. Our findings reveal the folding mechanism of the major cytoskeletal proteins tubulin/actin under the coordination of the biogenesis machinery TRiC and plp2 and extend our understanding of the links between cytoskeletal proteostasis and related human diseases. Structural basis of plp2-mediated cytoskeletal protein folding by TRiC/CCT.,Han W, Jin M, Liu C, Zhao Q, Wang S, Wang Y, Yin Y, Peng C, Wang Y, Cong Y Sci Adv. 2023 Mar 17;9(11):eade1207. doi: 10.1126/sciadv.ade1207. Epub 2023 Mar , 15. PMID:36921056[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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