FIG 4.
Ribosome-targeting antibiotics increase steady-state ermB mRNA levels independently of ErmBLEF-mediated ribosome stalling. (A) Quantitative RT-PCR analysis demonstrated an increase in ermB mRNA abundance after ERY treatment in different ermBLEF mutant backgrounds. The fold change relative to the untreated WT is shown. (B) Quantitative RT-PCR analysis demonstrated that the noninducers of ErmBLEF-mediated ribosome stalling, clindamycin (CLN) and tylosin (TYL) (see Fig. S4 in the supplemental material) (58), upregulate ermB expression. Total RNAs were isolated from the WT ermBLEF-ermB strain treated with different antibiotics. The fold change relative to the untreated sample is shown. Error bars indicate the standard deviation of three replicates.