FIG. 3.

Effect of MarR on gyrase activity. The mix constituents are 0.5 μg of pUC19 relaxed, 1 unit (120 pmol) of purified E. coli DNA gyrase (4.1 μM) and 250 pmol (8 μg) of purified MarR (8.3 μM). Samples were incubated at 37°C for 30 min, subjected to electrophoresis in a 0.8% agarose gel, and stained after migration by ethidium bromide (see Materials and Methods).