The long-term goal of this research is to understand how organisms coordinate the replication and repair of their genomes. The use of processivity clamps that must be loaded onto DNA during replication of chromosomes by an ATP dependent clamp loader complex is highly conserved by all forms of life. Understanding how organisms coordinate DNA replication and repair is the fundamental basis for understanding human diseases such as cancer. The goal of the work proposed here is to better define the mechanism of clamp loading in the E. coli model system. The E. coli clamp loader (gamma complex) is a multisubunit complex that undergoes a conformational change upon binding ATP which facilitates opening of the beta clamp and its subsequent loading onto DNA. The contacts of the individual clamp loader subunits with beta differ between the ATP bound and free states of gamma complex. The interactions of the gamma complex subunits with beta in both the presence and absence of ATP will be determined. Biochemical assays using various clamp and clamp loader mutants will be utilized to accomplish this. The insight gained from E. coli can provide a framework for elucidating the mechanisms of eukaryotes, including humans.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31GM073586-02
Application #
7051413
Study Section
Special Emphasis Panel (ZRG1-IDM-L (29))
Program Officer
Gaillard, Shawn R
Project Start
2005-04-02
Project End
2008-04-01
Budget Start
2006-04-02
Budget End
2007-04-01
Support Year
2
Fiscal Year
2006
Total Cost
$25,448
Indirect Cost
Name
State University of New York at Buffalo
Department
Biochemistry
Type
Schools of Medicine
DUNS #
038633251
City
Buffalo
State
NY
Country
United States
Zip Code
14260
Scouten Ponticelli, Sarah K; Duzen, Jill M; Sutton, Mark D (2009) Contributions of the individual hydrophobic clefts of the Escherichia coli beta sliding clamp to clamp loading, DNA replication and clamp recycling. Nucleic Acids Res 37:2796-809
Heltzel, Justin M H; Scouten Ponticelli, Sarah K; Sanders, Laurie H et al. (2009) Sliding clamp-DNA interactions are required for viability and contribute to DNA polymerase management in Escherichia coli. J Mol Biol 387:74-91
Heltzel, Justin M H; Maul, Robert W; Scouten Ponticelli, Sarah K et al. (2009) A model for DNA polymerase switching involving a single cleft and the rim of the sliding clamp. Proc Natl Acad Sci U S A 106:12664-9