FIG. 2.

Genetic organization of the region encoding rhizobactin biosynthesis (rhb), regulation (rhr), and transport (rht) genes in S. meliloti. The DNA sequences upstream of rhtX and between rhrA and rhtA are shown, having the six-base repeat (underlined) interspersed by 15 bases. Identical sequences in the two regions are shown in boldface. The locations of the kanamycin cassette insertions in the mutants 2011Sma2335km and 2011rhtX1 are shown (▿). The location of the Tn5lac insertion in mutant 2011rhtX43 is also shown (▾). Start codons are in italic. The CT repeats are in boldface italic. Restriction sites: A, ApaI; B, BamHI; E, EcoRI; P, PstI; X, XhoI; Xb, XbaI.