Distinct ways by which Srs2 helicase and Rrp1 translocase shape Rad51-DNA interactions in fission yeast.

Srs2 helicase and Rrp1 translocase differentially regulate Rad51-DNA interactions in fission yeast, targeting distinct Rad51 pools through substrate specificity.

• Why it matters: Understanding how anti-recombinogenic enzymes control Rad51 is crucial for insights into genome stability and cancer, yet their specific actions on Rad51 pools remain unclear.
• What they did: Using Schizosaccharomyces pombe, the study analyzed genetic interactions and found Srs2 preferentially regulates Rad52-dependent Rad51 on ssDNA, while Rrp1 targets Rad51 on double-stranded DNA, with Rrp1 alleviating Rad51 overproduction toxicity.
• The result: Both enzymes restrict Rad51 at centromeres, but only Srs2 acts within rDNA repeats; excess Srs2 promotes Rad51 accumulation, indicating that these enzymes differentially modulate Rad51 based on DNA substrate, balancing DNA repair functions.