FIG. 6.

E2 binding sites in the HPV-16 promoter positively and negatively modulate E1 expression and ORI function. (A) Mutation of E2 sites both positively and negatively influence HPV-16 initial amplification in transiently transfected SCC13 cells as measured by Southern blotting. (B) Complementation of E1 function in transient replication assays using mutated HPV-16 constructs (as illustrated in Fig. 1), where E2#1−,#2− and E2#3−,#4− indicate mutations of the P97 promoter-proximal and -distal E2 binding sites, respectively. Linearized HPV-16 genome (30 pg) was included as a positive blotting control.