<p>A) Schematic representation of the proposed conformational structure of IAV-WSN wild type NP UTR in corkscrew or panhandle conformation (left panel; refs 10 and 30) and the improved base-pairing by panhandle-stabilizing mutations in the 3′ (NPph) or 5′ (NPphR) UTR (right panel). B) Normalized ratio of firefly to <i>Gaussia</i> luciferase activity (Fluc/Gluc) after single or co-transfection of FNP and different versions of the extended <i>Gaussia</i> reporter construct carrying either NP, NPph or NPphR UTRs (GFsNP, GFsNPph, and GFsNPphR, respectively). C) Normalized ratio of firefly to <i>Gaussia</i> luciferase activity (Fluc/Gluc) after single or co-transfection of firefly luciferase constructs with NP or NPphs UTR (FNP and FNPph, respectively) and the short or extended <i>Gaussia</i> reporter construct carrying either NP (GNP and GFsNP) or NPph (GNPph and GFsNPph) UTRs.</p
