FIG. 4.

(A) Nicking at R1162 oriTs (core plus inner arm) mutated within the conserved sequence AAA in the inner arm. The nick is shown by the arrowhead. Nicking was assayed by primer extension. The unmutated, conserved DNA is lane AAA, adjacent to the sequencing ladder. The other lanes contain conserved DNA with the sequence shown at the top of the figure. (B) Sensitivity of mutated oriT DNA to oxidation by permanganate. DNA was assayed by primer extension as in panel A, except that the complement to the nicked strand was used as the template. Plasmid DNAs were extracted from cleared lysates treated (+) or untreated (−) with permanganate.