Fig. 6

ermBL2 is not critical for the induction of ermB expression by spiramycin and tylosin. A The detailed RNA and amino acid sequences of ermBL, ermBL2 and their own ribosome binding sites (RBS3). B-E Mutation of the start codon (GTG) of ermBL2 to alanine (GCG, GCT, GCC, GCA). β-Galactosidase activity and disk diffusion assays of the activation of the lacZα reporter in response to Ery and 16-membered ring macrolides in vivo. F–H Mutation of the start codon (GTG) of ermBL2 to other start codons (ATG, CTG, TTG). β-Galactosidase activity and disk diffusion assays of the activation of the lacZα reporter in response to Ery and 16-membered ring macrolides in vivo. I-K Mutation of the start codon (GTG) of ermBL2 to stop codons (TAG, TGA, TAA). β-Galactosidase activity and disk diffusion assays of the activation of the lacZα reporter in response to Ery and 16-membered ring macrolides in vivo. Miller units of β-galactosidase activity are shown on the Y-axis. The number on the top of each bar represents the fold change in beta-gal activity between the antibiotic and DMSO group. The error bars correspond to the SEM of three independent experiments. All the β-Galactosidase activity of antibiotics group compared to DMSO group is significantly. P < 0.05; (unpaired two-tailed Student’s t test)