Bacterial growth inhibition by roxithromycin (pH 8.9) in cultures overexpressing Rob-wt protein or suppression of a Rob gene having a TAG codon at protein position 40 by a specific amino acid. Abbreviations: wt, wild type; no, no Rob protein sequence in the vector; Rob40–1, Rob40–2, Rob40–3, Rob40–4, Rob40–F, and Rob40–L, Rob40 with nucleobase amino acids 1, 2, 3, 4, Phe, and Leu at position 40 instead of Arg, respectively. Rob40–1 vs Rob-wt: p < 0.05. Rob40–2 vs Rob-wt: p > 0.05.