AUTHOR=Stiles Bradley G., Wigelsworth Darran J., Popoff Michel R., Barth Holger 

TITLE=Clostridial Binary Toxins: Iota and C2 Family Portraits

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=1

YEAR=2011

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2011.00011

DOI=10.3389/fcimb.2011.00011

ISSN=2235-2988

ABSTRACT=<p>There are many pathogenic <italic>Clostridium</italic> species with diverse virulence factors that include protein toxins. Some of these bacteria, such as <italic>C. botulinum</italic>, <italic>C. difficile</italic>, <italic>C. perfringens</italic>, and <italic>C. spiroforme</italic>, cause enteric problems in animals as well as humans. These often fatal diseases can partly be attributed to binary protein toxins that follow a classic AB paradigm. Within a targeted cell, all clostridial binary toxins destroy filamentous actin via mono-ADP-ribosylation of globular actin by the A component. However, much less is known about B component binding to cell-surface receptors. These toxins share sequence homology amongst themselves and with those produced by another Gram-positive, spore-forming bacterium also commonly associated with soil and disease: <italic>Bacillus anthracis</italic>. This review focuses upon the iota and C2 families of clostridial binary toxins and includes: (1) basics of the bacterial source; (2) toxin biochemistry; (3) sophisticated cellular uptake machinery; and (4) host–cell responses following toxin-mediated disruption of the cytoskeleton. In summary, these protein toxins aid diverse enteric species within the genus <italic>Clostridium</italic>.</p>