FIG 2 .

Design and properties of the ΔA23T7 vector system. (A) Features of the recombinant VACV genome of ΔA23T7/luc vector are depicted in the diagram. The early, intermediate, and T7 promoters are indicated in red and placed next to the ORFs encoding the T7 polymerase (T7 pol), lac repressor (lacI), and luc, respectively. Additional abbreviations: X, deleted A23 intermediate transcription factor gene; TT, triple-transcription terminator; SLO, modified lac operator; GFP, green fluorescent protein ORF; EMC leader, encephalomyocarditis virus (EMCV) translational enhancer region. (B) Predicted effects on gene expression in complementing and noncomplementing cells.