Mechanics and execution of homologous recombination - biophysics to the organism

Homologous recombination (HR) is an essential mechanism for the repair of DNA double-strand breaks and damaged replication forks and is associated with genetic disorders, cancer and aging. HR repairs DNA damage by copying the correct genetic information from an intact chromosomal template, which is critically dependent on the recombinase RAD51. To ensure its timely and accurate completion, HR is positively and negatively regulated by RAD51 co-factors and anti-recombinases. How these HR regulators function at the molecular level remains poorly understood and represents a significant challenge to the field due to the lack of mechanistic resolution afforded by conventional bulk biochemical approaches. We recently pioneered several cutting-edge biophysical approaches to interrogate the HR reaction in unprecedented detail. Importantly, we demonstrated the power of integrating data from these complementary methodologies to uncover the mechanism of action of the Rad51 paralogs in modulating RAD51 to promote HR. The aim of our proposal is to extend this paradigm to study multiple different HR regulators to gain insights into how they work individually and how they act cooperatively during HR. Deciphering how HR regulators work will provide an improved understanding of the molecular mechanisms relevant to carcinogenesis and may present unique opportunities for therapeutic intervention.