Cooperativity and communication in archaeal Cdc48·20S, an ancient proteolytic machine
Author(s)Grabenstatter, Jonathan Dean
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences.
Robert T. Sauer.
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ATP dependent proteolysis is a process essential for life and is carried out by AAA+ proteases. AAA+ unfoldases use the energy of ATP hydrolysis to power the unfolding and translocation of protein substrates into compartmentalized peptidases for regulated proteolysis. Cdc48 is a highly conserved AAA+ homohexameric unfoldase which is made up of two AAA+ rings. Each ring can, in principle, bind and hydrolyzing ATP, but it is unclear what roles are played by each ring and how they coordinate their activities. A regulatory N domain functions to control the activity of the enzyme and binding to its partner peptidase, the 20S proteasome. In this thesis I present experiments which investigate the role of inter-ring communication in ATP hydrolysis, protein unfolding, and allosteric interactions with the 20S and show how these features affect enzyme function. Experiments also show how the N domain controls D1-D2 interactions that govern ATP hydrolysis and substrate unfolding. Finally, I present experiments that take steps toward developing a system for screening protein substrates of Cdc48-20S and identify several substrates from E. coli lysates.
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2015."September 2015." Cataloged from PDF version of thesis.Includes bibliographical references.
DepartmentMassachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Massachusetts Institute of Technology
Earth, Atmospheric, and Planetary Sciences.