Fig 1.

Effects of mutations in the erm(B) region on dimethylation at A2058 in 23S rRNA. (A) Diagram representing the erm(B) region in Tn3872 and the mutant erm(B) region of S1. (B) Secondary structure of translationally inactive form of the regulatory region of erm(B) mRNA and mutations detected in the parental strain S1. RBS2, ribosome-binding site; S2, start codon of the methyltransferase structural gene. (C) Levels of dimethylation at A2058 in 23S rRNAs extracted from strain S1 cultured with and without ERY. Dimethylated A2058 was detected by reverse transcriptase extension from bases 2066 to 2101. Dimethylation at A2058 aborts the extension.