FIG. 1.

Schematic representation of the HPV-18 URR. The 824-bp HPV-18 URR is located within the 1,049-bp BamHI fragment of the HPV-18 genome. The URR consists of 5′ distal (positions −824 to −450), central (positions −450 to −221), and 3′ proximal (positions −221 to −1) fragments. The transcription initiation site is indicated by a crooked arrow. The relative positions of the distal YY1 site, the central overlapping AP-1 and YY1 sites, the C/EBPβ-YY1 site, the promoter-proximal AP-1 and YY1 sites, and the TBP-TATA box binding site are indicated.