FIG. 1.

(A) Genomic context of the rsr gene. rsr lies in close proximity to three regulatory genes, sarR, sarY, and SA2092, which encodes a gene product with similarity to the AraC protein family. (B) Transcription (top) of rsr during the early, mid-, and late exponential phases of growth in strain SH1000. Numbers underneath the panels indicate relative intensities of the bands as determined by ImageJ. rRNA bands (middle) are shown as a loading control for the top panel. (C) Transcription (top) of rsr during the mid-exponential phase in the SH1000 parent, rsr mutant, and restored rsr mutant with a single copy of the rsr gene at its native chromosomal location. The intensities of the rRNA bands (bottom) serve as loading controls. (D) Translation of Rsr in the parent, mutant, and restored rsr mutant strains at late exponential phase as detected by a Western blot, with 20 μg of whole-cell lysate each and probed with a 1:1,000 dilution of murine anti-Rsr antibody (top). The bottom panel represents an equivalent SDS gel stained with Coomassie blue to demonstrate comparable loading among the lanes.