Conformational Switches in Action: A New Framework for Understanding Macromolecular Machines in Genome Maintenance

Macromolecular complexes perform essential cellular activities by harnessing chemical energy to drive biological processes. My recent discovery of the "entropy switch" mechanism in replicative helicases (Nature, 2025) established a new paradigm in understanding how such machines work, revealing that ATP hydrolysis achieves mechanical work not through power strokes – but by releasing constraints to permit molecular motions that drive function. Building on this breakthrough, I aim to establish an independent research program investigating how annealing helicases – SMARCAL1 and ZRANB3 – harness ATP to drive DNA rewinding during replication stress. Using my pioneering integration of time-resolved cryo-EM with AI-driven conformational analysis, I will: (1) dissect SMARCAL1's mechanism for displacing RPA from single-stranded DNA, (2) reveal how ZRANB3 employs substrate-dependent conformational switching between annealing and nuclease activities, and (3) define how mechanochemical coupling drives reverse reactions in these specialised enzymes. This work will address fundamental questions about energy transduction while providing mechanistic insights into diseases caused by annealing helicase mutations. The Accelerator Award will accelerate my transition to independence and establish the foundation for investigating diverse genome maintenance complexes. It will enable me to develop leadership skills, build preliminary data for major funding applications, and establish my distinctive scientific identity.