Figure 1.

Strand transfer reactions with Tn552kan. (A) Tn552kan: the shaded boxes represent the 23-bp binding sites at the transposon ends. The asterisks indicate the position of the ³²P label. (B) Transposition reactions (3 hr) contained 270 ng of supercoiled or PstI-linearized pUC19 as target, about 50 fmol of a mixture of unlabeled and ³²P-labeled Tn552kan as the substrate, 120 ng transposase, and 10 mM MgCl₂ or MnCl₂ as indicated. Reactions run in lanes 3, 5, 10, and 12 were digested with PstI. Reaction products were resolved by agarose gel electrophoresis and detected by both ethidium bromide staining (Right) and autoradiography (Left). The predicted structures of the reaction products are shown; thin lines and thick lines represent the substrate and target DNAs, respectively. oc, open circle form of pUC19; lin, linear pUC19; ccc, covalently closed circular form of pUC19.