FIG. 5.

Nucleotide insertions and deletions within the −11/+1 region can alter the site for initiation. (A) The sequence of the WT proscript is presented as described in the legend to Fig. 2A. Nucleotides inserted in mutant proscripts are denoted in the gap in the WT sequence. Empty boxes denote deletions of specific nucleotides. Changes of nucleotides in the template sequence are indicated by letters at the ends of the dashed lines. (B) Autoradiograph of RdRp products synthesized from proscripts containing insertions and deletions within the −11/+1 region of the subgenomic promoter. Duplicate independent reactions are shown, and the sizes of the products are indicated on the left. The arrow points to a 10-nt product visible in lanes 7 and 8. Lane 8 is marked with an asterisk because the level of products in this lane is lower due to loss of sample during the assay. (C) Quantitation of the 13/14-nt, 11/12-nt, and 15/16-nt products initiated from nt +1, +3, and −2. Products are quantitated relative to synthesis from WT. The column on the right represents the value of the total amount of all products synthesized. Values for 1 standard deviation from the mean are listed and represent at least three independent assays.