Fig. 1.
The expression vector pcDNA3-BM40-HisEK that is based on the mammalian CMV promoter-driven pcDNA3 vector. It adds a BM40 signal peptide for exporting proteins to the medium followed by a hexa-histidine tag for purification and an enterokinase D cleavage site N-terminal of the recombinant protein to cleave off the BM40 signal and histidine tag.