FIG. 7.

Competition assay of IVa2 binding to the packaging sequence probe. EMSAs were performed as described in the legend to Fig. 4, using either a 100 or 1,000-fold molar excess of the indicated unlabeled A-repeat DNA competitors. The IVa2-packaging sequence probe complexes and the free probe are indicated with a bold line and an arrowhead, respectively. The presence or absence of IVa2 in the binding reaction is indicated with a + or −, respectively. The first two lanes lack competitor. The triangles above the lanes indicate increasing concentrations of the competitors.