Figure 2.

Analysis of point mutations at the 7/8 site. The 7/8 and mutant templates were transcribed as described in Materials and Methods, with SII included in the reactions as indicated. RNA lengths taken from the single NTP limiting marker reactions (generated on the NA2 template) are given on the left and right, respectively. Sequences listed below are the 50 bp fragments inserted in the pML20-42 plasmid to generate each template (see Materials and Methods). In this and the following figures, sequences from the TH gene are underlined, distances downstream of +1 are given below the sequences and arrest positions are indicated by dots above the last nucleotide to be incorporated into the transcript.