Cytolethal Distending Toxin: A Unique Variation on the AB Toxin Paradigm

Figure 1

Structure comparisons of representative AB toxins. Structures of the A and B chains are shown as ribbon backbone models generated with UCSF Chimera 1.8.1. The anthrax B chain is depicted as the assembled heptamer. Three to four A1 or A2 chains or combinations of both chains are assembled in the holotoxin. The boxed structure shows the B chain monomer. Protein data bank (PDB) files: 2AAI (ricin and viscumin), 1R4Q (Shiga toxin), 1J7N (LF), 1XFY (EF), 1TZN (PA), 2F2F (AaCdt), and 1SR4 (HdCdt).