Spatial organization of the Bordetella alcABCDER alcaligin siderophore operon. The linear genetic map depicts an approximately 8-kb BamHI-PstI chromosomal DNA region of B. bronchiseptica B013N. Arrows indicate the transcriptional orientations and genetic limits of genes of the alcABCDER operon, and open circles represent the locations of known Fur-regulated promoter-operator regions upstream from alcA, alcR, and fauA. Numbered open arrows indicate the positions and transcriptional orientations of the promoterless lacZ reporter genes associated with the mini-Tn5 lacZ1 transposon insertions of alcaligin-deficient mutants BRM1, BRM6, and BRM9. Abbreviations: B, BamHI; Sp, SphI; P, PstI; E, EcoRI; Sm, SmaI; K, KpnI; RV, EcoRV; Bg, BglII.