The chaperonin GroEL nano-machine: allostery and function

Chaperonins are nano-machines that are built of two back-to-back stacked heptameric rings. They assist protein folding by undergoing large conformational changes that are controlled by ATP binding and hydrolysis. In the E. coli cell, only about 60 different proteins require GroEL for efficient folding. In the first part of the talk, I will describe work that was aimed at determining the properties that distinguish GroEL clients from non-clients. In the second part of the talk, I will describe the impact of encapsulation on the stability of protein substrates. In the third part of the talk, I will describe new approaches for elucidating allosteric mechanisms. Using these approaches, it has been possible to show that GroEL undergoes concerted intra-ring conformational changes. By contrast, the eukaryotic homologue CCT/TRiC undergoes sequential intra-ring conformational changes. The impact of these different allosteric mechanisms on the folding functions of GroEL and CCT/TRiC will be discussed.

12/05/2023 ore 13, Aula A CU010 Prof. Amnon Horowitz Department of Chemical and Structural Biology Weizmann Institute of Science Rehovot, Israel

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