FIGURE 2.

D-loop formation promoted by Mhr1. [³²P]ssDNA oligonucleotides (1.0 μm final concentration after dsDNA was added; SAT-1 from pGsat4) were incubated with 1.95 μm Mhr1 for 5 min, and then negatively supercoiled homologous (pGsat4; lanes 1–4, 6, 7, 9, and 19) or heterologous (φX174) cc-dsDNA (15 μm) was added, and the samples were incubated at 37 °C for the indicated periods of time. After the proteins were removed, the products were analyzed by agarose gel electrophoresis. Control samples were as follows. Lanes 5, 11, and 14, heterologous combination; lanes 8 and 10, no protein; lanes 12–14, E. coli RecA (5 μm) instead of Mhr1 with 13 mm Mg²⁺ and ATP.