Fig. S3.

Composition of the homopolymeric tract determines the maximum length of reiterative transcripts. In vitro transcription assays were performed with the DNA scaffold containing pyrG variants (A) having homopolymeric tract in the initially transcribed template DNA (sequences of the transcription start site of each template and their RNA products are indicated below B–D). Transcription assays were performed in the presence of GTP (B), ATP (C), or CTP (D) {100 μM NTP plus 1 μCi [γ-³²P]GTP, [γ-³²P]ATP, or [α-³²P]CTP}. The positions of the reiterative products are indicated.