FIG. 3.

Mapping the 3′ ends of the monocistronic pagA transcript and determining the effects of CO₂ and atxA on pagR expression. RNase T2 protection assays were performed with 20 μg of RNA. (A) Locations of antisense riboprobes, the Ωkm-2 insertion in UT119, and the transcription attenuator are shown. (B) Lane 1: riboprobe 1 was hybridized to RNA from UM44 grown in 5% CO₂. RNase T2-protected fragments are indicated. Lanes 2 and 3: nucleotide size markers, as indicated. (C) Riboprobe 2 was hybridized to RNA from cells grown in 5% CO₂ or in air, as indicated. RNase T2-protected fragments are shown. Size markers are as indicated. The probe is 1,167 nt (including 222 nt of vector-derived sequences).