DOI

10.17077/etd.zy8rz6sv

Document Type

Dissertation

Date of Degree

Summer 2016

Degree Name

PhD (Doctor of Philosophy)

Degree In

Biochemistry

First Advisor

Washington, M. Todd

First Committee Member

Spies, Maria

Second Committee Member

DeMali, Kris

Third Committee Member

Fuentes, Ernesto

Fourth Committee Member

Shea, Madeline

Fifth Committee Member

Houtman, Jon

Abstract

DNA damage causes replication forks to stall, which can ultimately lead to double strand breaks, chromosomal rearrangements, and cell death. Proliferating cell nuclear antigen is a clamp protein which encircles DNA and acts as a sliding platform for proteins that will act on the DNA, including polymerases. Replication fork stalling causes PCNA to be mono-ubiquitylated, resulting in a polymerase switch from the classical polymerases that perform replication to the Y-family polymerases which conduct translesion synthesis (TLS) to bypass the DNA damage and allow replication to continue. Y-family polymerases include DNA polymerases eta, kappa, iota, and Rev1. The mechanism by which these polymerases are assembled into multi-protein complexes which include PCNA has previously not been well-understood. The studies outlined below demonstrate that ternary complexes involving PCNA, Rev1, and pol η can adopt multiple conformations which can rapidly interconvert. Additionally, I have demonstrated that ubiquitin stimulates the catalytic activity of DNA polymerase eta through a novel interaction with the catalytic core. These studies represent significant progress towards understand the regulation of TLS polymerase activity through both recruitment to and activation by ubiquitylated PCNA.

Pages

ix, 195 pages

Bibliography

Includes bibliographical references (pages 171-195).

Copyright

Copyright © 2016 Elizabeth Marie Boehm

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