The pESG-IBA43 vector allows the expression of 6xHistidine/Strep-tag®-fusion-proteins in Mammalia. The vector carries the Human cytomegalovirus (CMV) immediate-early promoter for high-level expression of proteins, the 6xHistidine -tag for N-terminal and the Strep -tag® for C-terminal fusion to the recombinant protein as well as the Neomycin resistance gene for selection of stable cell lines. The expressed recombinant protein will be localized in the cytoplasm.