Fig. 1.
Effect of transient expression of wild-type and catalytic mutants of S. typhi CdtB in cultured cells. Cos-2 cells were transfected with vectors encoding M45 epitope-tagged S. typhi CdtB, the catalytic mutants CdtBH160Q and CdtBD195S, or C. jejuni CdtB. Cells were stained 48 h after transfection with a monoclonal antibody directed to the M45 epitope tag (anti-M45) to visualize cells expressing the different CdtB proteins and with 4′,6-diamidino-2-phenylindole (DAPI) to visualize the chromatin. Images were obtained with a Nikon Eclipse inverted microscope fitted with a Princeton Instruments (Trenton, NJ) MicroMAX digital camera. (Scale bar, 50 μm.)