Additional file 13: of Stationary phase persister formation in Escherichia coli can be suppressed by piperacillin and PBP3 inhibition

Figure S11. Confirmation of FtsITrunc and FtsI*Trunc expression by mass spectrometry. Cultures of MG1655 carrying pKG110-ftsITrunc, pKG110-ftsI*Trunc, or pKG110-gfp were grown overnight in the presence of 1 mM sodium salicylate (inducer). Cell suspensions were boiled and loaded into a polyacrylamide gel. Gel bands from 50 – 75 kDa (expected size of the truncated proteins ~59 kDa) were excised and analyzed by mass spectrometry. Peptide sequences for FtsITrunc or FtsI*Trunc covering 29 and 57 %, respectively, of the full length FtsI protein were obtained. Yellow highlighted sequences correspond to observed peptides. Red font corresponds to the active site mutation in FtsI* (Ser307Ala). FtsI fragments were not observed in the excised gel band from the GFP-expressing control. Further, none of the fragments from the cytoplasmic or transmembrane domain of FtsI were detected in any sample. (TIF 275 kb)