FIG. 2.

Analysis of growth and viability for nsP2 MTase-like domain mutants. BHK-15 cells were infected with wild-type (SINV) or mutant virus at the same MOIs. The lethal mutants R615A and R699A, as well as the small-plaque mutants K733A and R751A, were compared with wild-type virus for relative growth rates. At the indicated times, medium was replaced, virus titers were determined by a standard plaque assay, and incubation was carried out at 30°C for 48 h. R699A did not show any detectable virus release.