FIG. 1.
Expression of recombinant E1 from vEE1. (A) mRNA expression was under the control of the bacteriophage T7 RNA polymerase promoter (PT7) and terminator (T7ter). Cap-independent translation was directed by the EMCV UTR, which was fused to the 5′ end of the E1 ORF. The resulting operon was recombined into the TK gene (TKL and TKR) of vaccinia virus. The arrow indicates the direction of transcription, and the closed circle represents the T7 terminator of transcription. (B) Equal volumes of whole-cell lysates from HeLa cells infected with vTF-7.3 and vEE1 (+) or with vTF-7.3 alone (−) were resolved by SDS-PAGE on a 10% polyacrylamide gel and assayed for recombinant E1 protein by Western blot analysis with the E1 antiserum RL-070, biotinylated secondary antibody, and 35S-streptavidin. The image was generated by PhosphorImager analysis (Molecular Dynamics). The positions of molecular mass markers (in kilodaltons) are shown on the right.