Fig. 3.

The MACV 5′ hook ligand functions as a bona fide activator of RNA synthesis. (A) Activation of MACV L occurs independently of sequential 3′ or 5′ vRNA addition. Products of RNA synthesis were visualized and quantified as in Fig. 1, and the relative changes in RNA accumulation are shown in a bar graph below the gel image. (B) Temporal analyses of MACV L activity in the absence (Left, 3′ only) or presence (Right, 3′ + 5′) of the 5′ vRNA ligand. (Upper graph) Nonnormalized quantification of RNA product accumulation in the absence (circles) or presence (triangles) of the 5′ ligand. (Lower graph) The normalized percent activity of MACV L in the absence (circles) or presence (triangles) of the 5′ ligand. All in vitro RNA synthesis reactions were performed as in Figs. 2 and 3 with equimolar concentrations of 3′ promoter and 5′ ligand, except in A, where either the 5′ (lane 1) or 3′ (lane 3) vRNAs were omitted from the reactions.