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Publication Abstract from PubMed

The Chaperonin Containing Tailless polypeptide 1 (CCT) complex is an essential protein folding machine with a diverse clientele of substrates, including many proteins with beta-propeller domains. Here, we determine the structures of human CCT in complex with its accessory co-chaperone, phosducin-like protein 1 (PhLP1), in the process of folding Gbeta(5), a component of Regulator of G protein Signaling (RGS) complexes. Cryoelectron microscopy (cryo-EM) and image processing reveal an ensemble of distinct snapshots that represent the folding trajectory of Gbeta(5) from an unfolded molten globule to a fully folded beta-propeller. These structures reveal the mechanism by which CCT directs Gbeta(5) folding through initiating specific intermolecular contacts that facilitate the sequential folding of individual beta sheets until the propeller closes into its native structure. This work directly visualizes chaperone-mediated protein folding and establishes that CCT orchestrates folding by stabilizing intermediates through interactions with surface residues that permit the hydrophobic core to coalesce into its folded state.

Visualizing the chaperone-mediated folding trajectory of the G protein beta5 beta-propeller.,Wang S, Sass MI, Kwon Y, Ludlam WG, Smith TM, Carter EJ, Gladden NE, Riggi M, Iwasa JH, Willardson BM, Shen PS Mol Cell. 2023 Nov 2;83(21):3852-3868.e6. doi: 10.1016/j.molcel.2023.09.032. Epub , 2023 Oct 17. PMID:37852256^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.