Data from: Real-time imaging of rotation during synthesis by the replisome

During chromosome replication, unwinding by the helicase and synthesis by
the polymerases can lead to overwinding and supercoiling of DNA. The
mechanical consequences of these events and resulting local dynamics at
the replication fork are not well understood. To address these issues, we
developed a transverse DNA flow-stretching approach to spatially resolve
the parental, leading, and lagging strands in real-time. Using
bacteriophage T7 as a model system, this approach revealed bursts of
high-speed replisome rotation that support continuous DNA synthesis.
Surprisingly, excessive rotation does not reduce replisome speed, but
increases pausing, reduces processivity, and increases the number of
polymerases. Taken together, our observations reveal intrinsic pathways to
overcome challenges posed by unfavorable DNA topologies during DNA
replication.