FIG. 1.

Enzymatic probing of the Aeh1 mobE regulatory hairpin. (A) Genomic organization and regulatory elements of the Aeh1 nrd genomic region (9). Genes are indicated by arrows indicating the direction of transcription, with the gene names designated above the arrows. (B) Enzymatic cleavage sites generated by single-stranded nucleases RNase T₁ (G specific) and RNase A (U and C specific) and double-stranded nuclease RNase V₁. Lane 1, sequencing ladder generated by alkaline hydrolysis; lanes 2, 6, and 10, undigested RNA (labeled C); lanes 3 to 5, RNase A; lanes 7 to 9, RNase T₁; lanes 11 to 13, RNase V₁. Each series of digestions are shown by decreasing concentrations of the RNase. (C) Model of secondary structure of mobE regulatory hairpin based on enzymatic mapping and Mfold (29) predictions.