FIG. 1.
Expression of r-EDIII-T protein in E. coli. (A) Map of the expression plasmid. The synthetic rEDIII-T gene was inserted into the BamHI and HindIII sites of plasmid pQE30, in-frame with the vector-provided ATG and six-His tag-encoding sequence. Abbreviations are as follows: pT5/lac O, prokaryotic promoter under lac operator control; rEDIII-T, synthetic gene encoding the tetravalent antigen; t1 and t2, transcriptional terminators; Ori and AmpR, plasmid replication origin and ampicillin resistance marker, respectively. (B) Coomassie-stained denaturing gel showing the polypeptide profiles of E. coli harboring the plasmid in panel A before (lane U [uninduced]) and after (lane I [induced]) IPTG induction. Protein molecular mass markers were run in lane M; their sizes in kDa are shown to the left. The arrow to the right indicates the position of the rEDIII-T protein.