FIG. 3.

Representative Southern analysis of transiently replicating HPV31 and E2BS mutant DNAs in the presence of expression vectors for E1 or E2. SCC-13 cells were cotransfected with 2 μg of religated HPV31 or HPV31-BS1, -BS2, -BS3, or -BS4 and 0.5 μg of pSG5 (−), pSG31:E1 (E1), or pSG31:E2 (E2). Low-molecular-weight DNA was isolated 120 h after transfection of SCC-13 cells and analyzed as described for Fig. 2. The marker lane (M) contains 100 pg of linearized HPV31 genome. The arrow indicates the position of the replicated DNA.