Contribution of the fourteen conserved residues present in PrV vhs to RNase activity in vivo. Reporter plasmid, pRluc (encoding Renilla luciferase) was co-transfected with each one of the vhs constructs into human 293T cells. The effect of each vhs protein on reporter gene expression was evaluated based on luciferase activity. HSV-1 vhs (HSV) served as a positive control for PrV vhs-dependent RNase activity. The luciferase activities of three independent assays were plotted (A). A structure indicating the key residues of PrV vhs surrounding the Mg2+ in the protein was created by simulation (B).