Fig 5.

Polymerase activities of mutant PAs lacking the expression of N-truncated PAs. 293 cells were transfected with expression plasmids encoding PB2, PB1, NP, and a vRNA replicon possessing a firefly luciferase gene between the noncoding regions of WSN-NP vRNA, along with the indicated PA- or PA mutant-expressing plasmid. Twenty-four or 40 h later, the luciferase activity was quantified. The data are the means ± SD of eight independent experiments plotted as the percent activity with wild-type PA for each experiment.