Cooperativity and communication in archaeal Cdc48·20S, an ancient proteolytic machine

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.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2015

Author dc:creator

• Grabenstatter, Jonathan Dean

Advisor dc:contributor.advisor

• Robert T. Sauer.

• Earth, Atmospheric, and Planetary Sciences.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/101347

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/101347