FIG. 5.

Transcription-replication of a virus-like CAT reporter RNA with homospecific polymerase complexes at 37 and 33°C in QT6 cells and COS-1 cells. COS-1 cells (A) or QT6 cells (B) were infected for 1 h at an MOI of 5 PFU/cell with a recombinant vaccinia virus expressing the T7 RNA polymerase and then transfected with pT7-CAT-RT and four plasmids encoding the PB1, PB2, PA, and NP proteins derived from VIC or MAL viruses, including in the latter case either the wild-type MAL PB2 or the mutant MAL E627K-PB2, as indicated. Cell extracts were prepared and tested for CAT expression following 18 h of incubation at 37 or 33°C. For a given complex, the CAT levels measured at 33°C (grey bars) were compared to the CAT levels measured at 37°C (black bars). The mean ± SD values are from duplicate samples from one experiment representative of two independent experiments.