FIG 6.

Relative activity of IBV polymerase complexes harboring WT PA and the K338R mutant. 293T and MDCK cells were transfected with the GLuc minigenome plasmid and expression plasmids of the IBV polymerase complex (PB2, PB1, PA, and NP). Luciferase expression was measured from three different experiments. The average relative results were then determined based on the luciferase expression of either WT Vc_BR60 or Ym_WI01. Error bars denote SD. **, P < 0.01; ***, P < 0.001 (compared with the expression of pVc_BR60 and pYm_WI01, respectively).