Coordination of DNA Metabolism by Replication Protein A

NIH RePORTER · GM · R35 · $546,612 · view on reporter.nih.gov ↗

Abstract

Summary DNA metabolic processes including replication, repair, recombination, and telomere maintenance occur on single-stranded DNA (ssDNA). In each of these complex processes, dozens of proteins function together on the ssDNA template. However, when double-stranded DNA is unwound, the transiently open ssDNA is protected and coated by the high affinity heterotrimeric ssDNA binding Replication Protein A (RPA). Almost all downstream DNA processes must first remodel/remove RPA or function alongside to access the ssDNA occluded under RPA. Formation of RPA-ssDNA complexes trigger the DNA damage checkpoint response and is a key step in activating most DNA repair and recombination pathways. Thus, in addition to protecting the exposed ssDNA, RPA functions as a gatekeeper to define functional specificity in DNA maintenance and genomic integrity. The precise mechanisms of how RPA imparts functional specificity is poorly resolved. Towards addressing this gap in knowledge, our long-term goals are to answer the following questions: a) RPA physically interacts with over three dozen DNA processing enzymes. How are these interactions determined, regulated, and prioritized? b) RPA binds to ssDNA with high affinity (KD <10-10 M). How do DNA metabolic enzymes that bind to ssDNA with hundred-fold lower affinities remove RPA? c) RPA plays a role in positioning the recruited enzymes (with appropriate polarity) onto the DNA. What are the structural, kinetic, and thermodynamic properties that regulate this process? d) How are the DNA and protein interaction activities of RPA tuned by post translational modifications such as phosphorylation? RPA achieves functional dexterity through a multi-domained architecture utilizing several DNA binding and protein-interaction domains connected by flexible linkers. This flexible and modular architecture enables RPA to adopt a myriad of configurations tailored for specific DNA metabolic roles. This dynamic plasticity has hindered structural, biochemical

Key facts

NIH application ID
11324225
Project number
5R35GM149320-04
Recipient
SAINT LOUIS UNIVERSITY
Principal Investigator
Edwin Antony
Activity code
R35
Funding institute
GM
Fiscal year
2026
Award amount
$546,612
Award type
5
Project period
2023-05-01T00:00:00 → 2028-04-30T00:00:00