Figure 3

Sequences of the E6-1 and E6-2 amplicons generated from pHV101. (A) Diagram of the HPV16 long control region (LCR) and the E6 and E7 genes, whose sequences overlap partially. The E6-1 amplicon (645 bp) is generated first by direct PCR with the LCRS/E7AS primer pair and then the E6-2 (237 bp) amplicon is generated by nested PCR with the pU1M/pU2R primer pair. The scale in the lower part of the figure indicates the positions of LCR, the E6 and E7 oncogenes and the E6-1 and E6-2 amplicon sequences on the HPV16 genome. (B) The E6-645 insert sequence corresponds to the cloned E6-1 amplicon, spans nucleotides 26-671 (645 bp) of the HPV16 genome and is flanked by the LCRS and E7AS primers (white letters on black background) at the 5' and 3' ends, respectively; it contains 38% GC and is 99% identical to the E6-HPV16 ORF [10]. The fragment corresponding to the E2-237 amplicon (in italics) spans nucleotides 419-656 (237 bp) of the HPV16 genome and is flanked by the pU1M and pU2R primers (white italics on black background), respectively; its sequence contains 41% GC and is identical to the corresponding ORF sequence of the E6-HPV16 oncogene. The three gray italic letters on black background correspond to the overlapping bases of the pU2R and E7AS primers.