High-level expression of His-tagged proteins from a single vector is possible in three
different expression systems due to the presence of the T5 promoter/lac operator
transcription–translation system for expression in E. coli; the p10 promoter for baculovirusbased
expression in insect cells; and the CAG (CMV/actin/globin) promoter for expression
in mammalian cells. The pQE-TriSystem vector has the following features