Deletion of fleQ results in overexpression and secretion of MopA. Lane 1, PAGERuler unstained protein ladder (Thermo Scientific); lane 2, wild type; lane 3, MopA-OE; lane 4, MopA-KO + EV; lane 5, MopA-KO + pmopA. The top protein in the marker lane is 200 kDa. The box indicates the portion of the gel submitted for LC-MS/MS.