FIG. 2.

Promoter utilization. The products of primer extension reactions on RNA from cells grown under various conditions were run on a sequencing gel next to size markers (rightmost lane). Primer SOT4 was used. The carbon and nitrogen source is indicated, as is the phase of growth (e, exponential; s, stationary). The promoter from which the transcripts originate is noted. (The glycerol-arginine exponential-phase lane is from a different gel and is inserted here for presentation purposes).