FIG 5.
Antibiotics prolong ermB mRNA half-life. (A) The mRNA decay curves of ErmBLEF WT, Q5Stop, and R7Stop background strains after 10 min of exposure to erythromycin (ERY) and clindamycin (CLN). A rifampin chase experiment was performed in E. coli cells bearing the chromosomally located ermBL-ermB′. (B) Summary of the ermB mRNA half-lives determined from panel A. An asterisk (*) indicates statistical significance (t test P ≤ 0.05). Superscript numbers: 1, standard deviations obtained from three independent biological replicates; 2, means and standard deviations obtained from two replicates. ND, not determined. (C) Reverse transcription mapping shows that mRNA cleavage downstream of the ermBLEF SD is reduced in the presence of erythromycin (ERY). A 1× RNA input equals 4 μg of RNA template in primer extension. The start codon and SD of ermBLEF are boxed. The RNase E-targeting sequence is denoted by a blue line. FL, full-length cDNA. The “+1” indicates the transcription start site of ermBLEF-ermB.