FIG. 2.

(A) Organization of the alb operon and flanking chromosomal regions of the B. subtilis chromosome. Rectangular boxes indicate the positions of genes in the alb region. The arrows above the boxes indicate the transcription units deduced by the Bacillus genome sequencing project (30). Also shown are the locations of the alb operon and the sbo gene, as well as the genetically linked fnr gene and the fnr::spc insertion mutation (used to demonstrate linkage) (31). The integrative plasmid pE1 and the site of its recombination with the chromosome, which causes disruption of the alb operon, are shown. T, putative transcription termination site. (B) Location of the sbo::neo-1 and sbo::neo-2 insertions. (C) The stem-loop structure predicted from inspection of the sbo-albA intergenic-region sequence that overlaps with the 3′ end of the sbo gene (indicated in boldface). Also shown is the free energy of secondary-structure formation, ΔG.