Fig 3.

Mapping of SPPV 063 residues responsible for its specific defect in murine cells. (A) (Top) Schematic diagrams of SWPV 064 (white boxes) and SPPV 063 (shaded boxes) chimeras. (Bottom) Substitution mutations in SPPV 063 shown in the context of an amino acid sequence alignment of SWPV 064 and SPPV 063. The mutations are referred to by the positions of the SPPV 063 amino acids that are replaced. The phenotypes of the mutant viruses expressing these SPPV 063 mutations are summarized on the right. (B) Levels of mutated SPPV 063 proteins in Vero cells infected with mutant viruses for 8 h. The mutant viruses are referred to by the positions of the SPPV 063 mutations. Infections and Western blotting were performed as described in the legend to Fig. 2B. Expression levels of the VACV early protein D12L and the host protein Hsp70 were determined as controls for equal infection and gel loading, respectively. (C) Growth analysis of mutant viruses in HeLa cells and 3T3 cells. Cells were infected by the indicated mutant viruses at an MOI of 5 PFU/cell. Virus titers at 0 and 48 hpi were determined by plaque assay on permissive Vero cells.