Table 2.

Structural organization of the binary toxin family.

Toxin	Enzymatic component	Binding component
C. perfringens Iota-toxin	Ia	Ib
B. anthracis Toxin	Lethal factor	Protective antigen
	Edema factor
C. botulinum C2toxin	C2I	C2II
C. spiroforme Iota-like toxin	Sa	Sb