Binary Bacterial Toxins: Evolution of a Common, Intoxicating Theme
Bradley G. Stiles and Michel R. Popoff
from: Clostridia: Molecular Biology in the Post-genomic Era (Edited by: Holger Brüggemann and Gerhard Gottschalk). Caister Academic Press, U.K. (2009)
Several proteins from Gram-positive, spore-forming bacilli use a synergistic binary mechanism for intoxicating eukaryotic cells. These toxins include Clostridium botulinum C2 toxin, Clostridium difficile toxin (CDT), Clostridium perfringens iota (ι) toxin, and Clostridium spiroforme toxin (CST). Furthermore, closely related Bacillus species such as Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis produce strikingly similar binary toxins. As per existing literature, these latter proteins have provided a "model" for the clostridial binary toxins. Each of these clostridial and bacillus binary toxins consists of distinct enzymatic "A" and binding "B" proteins that work in concert. Conservation of a basic intoxication theme between different genera clearly suggests retention of an evolutionarily successful mechanism promoting bacterial survival and dissemination throughout Nature. In particular, this chapter highlights the existing literature linked to Clostridium binary toxins and their role in pathogenesis, structure, function, as well as current / future use as protein shuttles read more ...