FIG. 1.

Genetic organization of the 31,870-bp inserted DNA of pJS332 with three distinct DNA regions (I to III). (A) The locations and orientations of the ORFs described in this study are indicated by arrows. Genes of the iroBCDEN cluster are indicated by dark gray shading, black arrows indicate transposase genes, and IS elements and transposons are depicted as hatched boxes. Designations below the schemes represent genes with extensive homology to other bacterial alleles as shown in Table 2. (B) Structures of subcloned fragments of the iro gene cluster in pCR4-TOPO giving rise to pJS12 and pJS13 plasmids, as well as the structure of the mutated iroN and iroE genes in plasmids pJS14 and pJS15, respectively. Triangles indicate insertions of trimethoprim transposon to generate mutations of iroN and iroE genes.