FIG. 3.

Gyrase cleavage of Mu and D108 DNA. pBR322 Δ(EcoRI-BamHI) plasmids with cloned 1.4-kb central fragments from Mu (lanes 2 and 3) and D108 (lanes 4 and 5) were linearized by PvuII restriction digestion and then incubated with DNA gyrase in the presence of enoxacin. Following treatment with SDS and proteinase K, the DNA fragments were separated on a 1% agarose gel and stained with ethidium bromide. The expected fragment sizes for cleavage at the Mu gyrase site are ∼2.9 and 2.6 kb. Lane 1, molecular size markers. −, no gyrase; +, with gyrase.