In this issue of Structure, Bertelsen et al. determine the three-dimensional structures Haemophilus influenzae VapD toxin, a Cas-2 homolog, with and without its cognate neutralizing antitoxin, VapX, that together comprise toxin-antitoxin system. These reveal unique stoichiometry, two toxins neutralized simultaneously by one VapX antitoxin. The virulence-associated protein D, or VapD, is encoded...

Neutralization of Clostridium difficile toxin by Clostridium sordellii antitoxin was studied by cytotoxicity assay in tissue culture. The sources of toxin were stools from two patients with pseudomembranous colitis and a culture filtrate of C. difficile isolated from one of the patients. C. sordellii antitoxin was available either in monovalent form or as gas gangrene polyvalent antitoxin. The ...

Bacterial toxin-antitoxin (TA) complexes induce programmed cell death and also function to relieve cell from stress by various response mechanisms. Escherichia coli RelB-RelE TA complex consists of a RelE toxin functionally counteracted by RelB antitoxin. In the present study, a novel homolog of RelE toxin designated as Xn-relE toxin from Xenorhabdus nematophila possessing its own antitoxin des...