Figure 3

Roles of the bsc T3SS and the BteA effector in cytotoxicity. A. HeLa (blue bars), J774A.1 (red bars), or A549 cells (green bars) were infected with the indicated strains at a multiplicity of infection (MOI) of 50 in 24-well plates for 3 h. The bteA mutant strains were complemented in trans with the RB50 bteA allele carried on a medium copy vector (see Methods). Following infection, release of lactate dehydrogenase (LDH) into culture medium was measured as described in Methods. B. bteA homologues were compared using multialign [51] and amino acid differences are shown. Green lines indicate substitutions of highly conserved residues, blue shows weakly similar amino acids, red indicates no similarity, cyan dotted lines designate deletion of a residue and pink designates an amino acid insertion. Bp = B. pertussis, Bpp = B. parapertussis, LRT = lipid raft-targeting domain [12].