The bb0729 cdr operon. (A) Organization of the region surrounding bb0728 (cdr). Primers used to demonstrate the presence of a single transcript are indicated below the gene diagram; primers used for 5′-RACE to determine promoter location(s) are shown above the gene diagram. The region in which BosR potentially binds (Boylan et al., 2006) is indicated (BosR-BS). The transcriptional start site (*), ribosomal binding site (RBS) and −10/−35 elements, as determined by 5′-RACE, are shown within the region between bb0730 and bb0729. (B) bb0729 and the cdr gene are co-transcribed under the regulatory control of a promoter upstream of bb0729. C162 was grown to 5 × 107 cells/ml at 37°C under standard conditions. RNA was harvested, converted to cDNA, and analyzed by RT-PCR using the indicated primer pairs; the corresponding locations for the primers (Table 2) are shown in (A). Molecular weights are given in kbp.