FIG. 7.

Full-length E1 also binds as two monomers to the minimal ori. A mixing experiment similar to that shown in Fig. 4 was performed with full-length E1. Four reactions containing 5, 1.3, 0.6, and 0.3 ng of full-length E1 were incubated alone (lanes 1 to 4), together with 0.1 ng of full-length E2 (lanes 5 to 8), or with two different quantities of truncated E1(142–308) (2 and 0.4 ng) in the presence of 0.1 ng of full-length E2 (lanes 13 to 20) in 10-μl binding reactions containing probe with the BS12H high-affinity E2 binding site. The asterisk indicates the position of the intermediate complex which formed when E1 and truncated E1(142–308) were mixed together in the presence of E2. Lanes 9 and 10 contain truncated E1(142–308) alone at the two concentrations used in the mixing experiment; lanes 11 and 12 contain the two concentrations of E1(142–308) in the presence of the E2 DBD. After incubation for 30 min at room temperature, the reactions were analyzed by SDS-PAGE (6% gel).