The long-term goal of our research is to understand the replication of damaged DNA in eukaryotes at the thermodynamic, kinetic, and structural levels. DNA damage in the template strand blocks replication by classical DNA polymerases. Consequently cells possess a variety of non-classical DNA polymerases that can replace the classical polymerase stalled at sites of DNA damage and can replicate through the damage. Recent kinetic studies and structural studies have provided substantial insights into how these non-classical polymerases differ from classical polymerases and how they are able to accommodate DNA damage. It remains unclear, however, how non-classical polymerases are recruited to sites of DNA damage, how stalled classical polymerases are displaced from sites of DNA damage, and how replication accessory factors promote nucleotide incorporation opposite DNA damage by non-classical polymerases. To address these issues, we propose studies with the following three specific aims: (1) to determine the effect of other protein factors on nucleotide incorporation opposite DNA damage by non-classical polymerases, (2) to determine the mechanism of non-classical polymerase recruitment during translesion synthesis, and (3) to determine the mechanism of classical polymerase displacement during translesion synthesis. These studies will provide a clear understanding of exactly how non-classical polymerases replace classical polymerases at sites of DNA damage and how other protein factors contribute to the replication of damaged DNA. Furthermore, these studies will contribute to our understanding of the origins of mutations and cancers and will provide insight into their prevention.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM081433-02
Application #
7649411
Study Section
Molecular Genetics A Study Section (MGA)
Program Officer
Santangelo, George M
Project Start
2008-07-01
Project End
2013-06-30
Budget Start
2009-07-01
Budget End
2010-06-30
Support Year
2
Fiscal Year
2009
Total Cost
$264,232
Indirect Cost
Name
University of Iowa
Department
Biochemistry
Type
Schools of Medicine
DUNS #
062761671
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Powers, Kyle T; Washington, M Todd (2018) Eukaryotic translesion synthesis: Choosing the right tool for the job. DNA Repair (Amst) :
Kondratick, Christine M; Litman, Jacob M; Shaffer, Kurt V et al. (2018) Crystal structures of PCNA mutant proteins defective in gene silencing suggest a novel interaction site on the front face of the PCNA ring. PLoS One 13:e0193333
Powers, Kyle T; Lavering, Emily D; Washington, M Todd (2018) Conformational Flexibility of Ubiquitin-Modified and SUMO-Modified PCNA Shown by Full-Ensemble Hybrid Methods. J Mol Biol 430:5294-5303
Powers, Kyle T; Elcock, Adrian H; Washington, M Todd (2018) The C-terminal region of translesion synthesis DNA polymerase ? is partially unstructured and has high conformational flexibility. Nucleic Acids Res 46:2107-2120
Liu, Jie; Ede, Christopher; Wright, William D et al. (2017) Srs2 promotes synthesis-dependent strand annealing by disrupting DNA polymerase ?-extending D-loops. Elife 6:
Zhao, Linlin; Washington, M Todd (2017) Translesion Synthesis: Insights into the Selection and Switching of DNA Polymerases. Genes (Basel) 8:
Powers, Kyle T; Washington, M Todd (2017) Analyzing the Catalytic Activities and Interactions of Eukaryotic Translesion Synthesis Polymerases. Methods Enzymol 592:329-356
Boehm, Elizabeth M; Washington, M Todd (2016) R.I.P. to the PIP: PCNA-binding motif no longer considered specific: PIP motifs and other related sequences are not distinct entities and can bind multiple proteins involved in genome maintenance. Bioessays 38:1117-1122
Washington, M Todd (2016) DNA Polymerase Fidelity: Beyond Right and Wrong. Structure 24:1855-1856
Boehm, E M; Subramanyam, S; Ghoneim, M et al. (2016) Quantifying the Assembly of Multicomponent Molecular Machines by Single-Molecule Total Internal Reflection Fluorescence Microscopy. Methods Enzymol 581:105-145

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