Figure 3.

Tests for interactions in trans by BaeI and BplI. (a) Reactions in BaeI buffer (20 μl) contained BaeI endonuclease (0.1 U), 5 nM ³H-labelled pJM1 and the concentrations indicated on the x-axis of either a specific oligoduplex, duplex I (white circles), or a non-specific oligoduplex, duplex V (black circles). After 3 min at 25 °C, the reactions were quenched and the concentration of the linear DNA product determined. (b) Reactions were as for (a) except that the enzyme was BplI (1 U) and reactions were carried out at 37 °C in BplI buffer for 10 min. The plasmid pJM1 and duplex I both have one recognition site for BaeI and one for BplI (Supplementary Data, Figure S1). Duplex V has neither BaeI nor BplI sites (Supplementary Data, Figure S2).