Figure 8. SsbB stimulates E. coli Topoisomerase I activity.

Supercoiled plasmid DNA was incubated with 0.12 units of topoisomerase and with increasing amounts of purified SsbB, as indicated. Reactions were carried out at 37°C for 30 min. DNA was resolved on a 1% agarose gel and stained with ethidium bromide. Arrow heads indicate the relaxed and supercoiled forms of plasmid.