FIG 9.

Antimycin A is an SfbR2 ligand. (A) EMSAs of GST-SfbR2 with various antibiotics. Antibiotic concentrations are indicated above each picture. Ampicillin and kanamycin were dissolved in water, while antimycin A and chloramphenicol were resuspended in ethanol and tetracycline in 0.15 M NaOH. Ethanol or 0.15 M NaOH was used as a solvent control when needed. (B) Effect of antimycin A on transcription of SfbR2 target genes in vivo. Antimycin A was dissolved in ethanol and added to 24-h cultures at 10 or 50 μM. Total RNA was isolated 1 h later, and expression was assessed by RT-qPCR. Transcription of each gene is expressed relative to the control (ethanol added), which was assigned a value of 1. The expression level of of rrnA1 (encoding 16S rRNA) was used as a control. Error bars were calculated by measuring the standard deviations of the ratio values among three biological and three technical replicates of each sample. Fold change values are indicated below the panel. Primers are listed in Table 1.