Figure 2.

(A) Different methods for AG presentation in the BG envelope complex—BG themselves carry native AG (LPS, OMP, IMP, TCP, flagella, pili)—TA may be presented on the cell surface via fusion with OmpA—the PPS can be loaded with TA via MBP-SbsA-fusion proteins (1), by fusion of the TA with MBP (2) or as sole TA using the gene III signal sequence (3) Protein TA may be incorporated into the IM via E′, L′ or E′/L′-anchoring, biotinylated AG can be attached to E′-FXa-StrpA membrane anchors, DNA carrying the lac operator site can be attached to L′-anchored lacI repressor molecules—TA fused with SbsA-/SbsB proteins form S-layers in the PPS. (B) Model of lysis tunnel formation according to Schön et al.²³