FIG. 5.

RNase protection of a 148-nucleotide riboprobe for rhbF and a 100-nucleotide riboprobe for rhbA. Lane 1, RNA from 2011::Tn5 in which the Tn5 insertion is outside the rhizobactin regulon and does not affect rhizobactin 1021 regulation, biosynthesis, or transport; lane 2, RNA from mutant 2011 rhbA62. The Tn5lac insertion in mutant rhbA62 is located downstream from the 100-nucleotide region protected by the rhbA riboprobe, and therefore a signal for rhbA is observed. A 200-nucleotide riboprobe for the npt gene of Tn5 allows comparison of RNA levels in the reactions. RNA was prepared from cultures grown under iron-depleted conditions.