Figure 1.

Predicted structure of DsrA RNA. Mutations used in this work are indicated. The Δ1 mutation deletes the S-L above the line and similarly for the Δ2 mutation. The NcoI mutant substitutes the underlined sequence for the bracketed sequence within DsrA and similarly for the XhoI mutant. The NcoI* mutant (made by cutting, end filling, and religating the NcoI mutant DNA) had a sequence at the novel joint with a partial duplication of the site: UGUCCAUGCAUGGAA. The ΔNcoI-XhoI deletion derivative has the sequence UGGUGUCCAUGUCGAGUCC at the novel joint (underlined sequence from NcoI site, bold from XhoI site).