Substrate specificity of PlmS2. HPLC chromatograms 1, 3, and 5, Plm B control as well as acid- and alkali-degraded Plm B, respectively, incubated without PlmS2. Chromatograms 2, 4, and 6, corresponding reaction mixtures after 1 h of incubation with PlmS2. AU, arbitrary units.