FIG. 3.

Autoradiograph of a nondenaturing polyacrylamide gel showing the products of nicking reactions carried out in the presence of NS1 and HMG1 or NS1 alone. Substrates were ³²P-, 3′-end-labeled hairpin sequences in the flip orientation (lanes 1 and 2) or linear Sau3A fragments of plasmid DNA (lanes 3 to 8). Substrates contained viral sequences from R1 to nucleotide 5042 (the minimal origin derived from pAGA [lanes 3 and 4]) or from R1 to nucleotide 5046 (pR1-4AGA [lanes 5 and 6]), with flanking vector sequences at each end of the insert. Lanes 7 and 8 show products obtained with pR1-4AGA precut with MspI.