The goal of the work in this proposal is to understand how DNA recombinase enzymes function at the molecular level. Our studies will focus on the bacterial RecA and human Rad5l (HsRad5l) proteins whose activities are of fundamental importance for the maintenance of genomic integrity. In bacteria, RecA is the central regulatory and catalytic component of a DNA-damage inducible recombinational repair system. In humans and other vertebrates, Rad5l is essential for survival and is a central component of a complex set of proteins involved in the catalysis of homologous genetic recombination and recombinational DNA repair. We have recently characterized an unexpected difference between RecA and HsRad5l regarding the regulation of their activity by ATP-mediated allosteric events and will exploit this finding in developing further studies of HsRad5l. We will use a combination of genetic and biochemical methods to address specific mechanistic questions about each enzyme. Studies are also designed to understand how the interaction of HsRad5l with other recombination proteins contributes to its function. Our work addresses questions regarding the molecular nature of conserved aspects of bacterial and human homologous recombination, while at the same time identifying features unique to the human proteins. Understanding the underlying molecular mechanistic principles of such proteins has far-reaching effects in ultimately being able to create novel proteins with desired properties that may be used for prevention of diseases resulting from genomic instability and for beneficial genetic manipulation.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM044772-11
Application #
6621966
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Program Officer
Anderson, Richard A
Project Start
1991-09-01
Project End
2006-02-28
Budget Start
2003-03-01
Budget End
2004-02-29
Support Year
11
Fiscal Year
2003
Total Cost
$310,050
Indirect Cost
Name
University of Massachusetts Medical School Worcester
Department
Biochemistry
Type
Schools of Medicine
DUNS #
603847393
City
Worcester
State
MA
Country
United States
Zip Code
01655
Sage, Jay M; Knight, Kendall L (2013) Human Rad51 promotes mitochondrial DNA synthesis under conditions of increased replication stress. Mitochondrion 13:350-6
Sage, Jay M; Gildemeister, Otto S; Knight, Kendall L (2010) Discovery of a novel function for human Rad51: maintenance of the mitochondrial genome. J Biol Chem 285:18984-90
Bakhlanova, Irina V; Dudkina, Alexandra V; Baitin, Dima M et al. (2010) Modulating cellular recombination potential through alterations in RecA structure and regulation. Mol Microbiol 78:1523-38
Gildemeister, Otto S; Sage, Jay M; Knight, Kendall L (2009) Cellular redistribution of Rad51 in response to DNA damage: novel role for Rad51C. J Biol Chem 284:31945-52
Bennett, Brian T; Bewersdorf, Jorg; Knight, Kendall L (2009) Immunofluorescence imaging of DNA damage response proteins: optimizing protocols for super-resolution microscopy. Methods 48:63-71
Forget, Anthony L; Kudron, Michelle M; McGrew, Dharia A et al. (2006) RecA dimers serve as a functional unit for assembly of active nucleoprotein filaments. Biochemistry 45:13537-42
Forget, Anthony L; Bennett, Brian T; Knight, Kendall L (2004) Xrcc3 is recruited to DNA double strand breaks early and independent of Rad51. J Cell Biochem 93:429-36
Skiba, M C; Knight, K L (1994) Functionally important residues at a subunit interface site in the RecA protein from Escherichia coli. J Biol Chem 269:3823-8
Nastri, H G; Knight, K L (1994) Identification of residues in the L1 region of the RecA protein which are important to recombination or coprotease activities. J Biol Chem 269:26311-22
Konola, J T; Logan, K M; Knight, K L (1994) Functional characterization of residues in the P-loop motif of the RecA protein ATP binding site. J Mol Biol 237:20-34

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