Critical Interaction Domains Between Bloom Syndrome Protein and RAD51

The American Cancer Society's 2009 statistics estimate that 1 out of every 4 deaths is cancer related. Genomic instability is a common feature of cancerous states, and an increase in genomic instability is the diagnostic feature of Bloom Syndrome. Bloom Syndrome, a rare disorder characterized by a predisposition to cancer, is caused by mutations of the BLM gene. This study focuses on the partnerships of BLM protein to RAD51, a Homologous Recombination repair protein essential for survival. A systematic set of BLM deletion fragments were generated to refine the protein binding domains of BLM to RAD51 and determine interacting regions of BLM and ssDNA. Results show that RAD51 and ssDNA interact in overlapping regions; BLM₁₀₀₋₂₁₄ and BLM₁₃₁₇₋₁₃₆₇. The overlapping nature of these regions suggests a preferential binding for one partner that could function to regulate homologous recombination and therefore helps to clarify the role of BLM in maintaining genomic stability.