FIG. 2.

E2 synthesis. (A) BS-C-1 cells were infected with 10 PFU per cell of VACV strain WR, and whole-cell extracts were prepared at the indicated times. Extracts from mock-infected cells and cells infected in the presence of cytosine arabinoside (AraC) were also prepared, and all extracts were analyzed by SDS-PAGE and Western blotting with rabbit antiserum to E2 followed by anti-rabbit immunoglobulin G conjugated to horseradish peroxidase. h.p.i., hours postinfection. (B) Comparison of E2L with intermediate and late promoters. Plasmids containing the E2L ORF preceded by the E2L promoter, the G8R intermediate promoter (P.Inter), or the F17R late promoter (P.Late) were transfected into cells that had been infected with VACV in the presence (+) or absence (−) of AraC. After 24 h, the cells were harvested, and lysates were analyzed by Western blotting as for panel A. The positions and masses of marker proteins are indicated on the left.