Construction of the recombinant plasmids used for DNA – (a) and protein-delivery (b). Both approaches use the same plasmid backbone consisting of an E. coli origin of replication (oriE1), repD and repE as genes needed for listerial replication, a erythromycin resistance cassette (ermAM) and the gene needed for the balanced lethal system trpS with its own promoter (P
). (a) The genes egfp, deoD, and fcu1 were inserted under the control of the PCMV or P4XTETP promoters and fused to a poly-adenylation signal. The autolysis cassette consists of the phage lysin gene ply118 under the control of the listerial promoter P
. (b) The E. coli-derived gene deoD is put under the control of P
and genetically fused to the signal sequence (SP) for Sec-dependent secretion of ActA.