FIG. 6.

In vivo gyrase cleavage. Lysogens with prophages carrying either the Mu SGS or the pSC101 gyrase site were grown in L broth, enoxacin was added to 300 μg/ml for 5 min, and the cells were rapidly lysed in hot SDS. DNA was isolated, treated with proteinase K, and digested with the appropriate restriction enzyme. One-directional PCR with primers near the gyrase sites yielded shorter fragments from templates that were cleaved by gyrase and longer fragments from templates not cleaved by gyrase. A sequencing ladder provided size markers (base pairs).