Torsion is a dynamic regulator of DNA replication stalling and reactivation.

ABSTRACT: DNA's helical structure necessitates replisome rotation relative to DNA during replication, creating inevitable topological challenges. How replication generates and overcomes torsional stress remains unclear. Here, we developed a high-resolution, label-free, real-time assay to track DNA rotation by T7 replisome and its slowing under torsional stress. While helicase or DNA polymerase (DNAP) alone is a weak rotary motor, together they form the most powerful DNA rotary motor yet studied, generating ~22 pN·nm torque before stalling, twice that of E. coli RNA polymerase. Upon stalling, helicase-DNAP interactions stabilize the fork; without them, regression can extend hundreds of base pairs. Prolonged stalling inactivates the replisome, but excess DNAP, aided by interactions with helicase, prom

SUBMITTER: Jia X 

PROVIDER: S-EPMC12658067 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature