Anthrax toxin receptor 2 <p>Anthrax is an acute disease in humans and animals caused by the bacterium <taxon tax_id="1392">Bacillus anthracis</taxon>, which can be lethal. There are effective vaccines against anthrax, and some forms of the disease respond well to antibiotic treatment. The anthrax bacillus is one of only a few that can form long-lived spores.</p><p>The anthrax toxin consists of the proteins protective antigen (PA) lethal factor (LF) and oedema factor (EF). The first step of toxin entry into host cells is the recognition by PA of a receptor on the surface of the target cell. The subsequent cleavage of receptor-bound PA enables EF and LF to bind and form a heptameric PA63 pre-pore, which triggers endocytosis. PA has been shown to bind to two cellular receptors: anthrax toxin receptor/tumour endothelial marker 8 and capillary morphogenesis protein 2 (CMG2), which are closely related host cell receptors. Both bind to PA with high affinity and are capable of mediating toxicity [<cite idref="PUB00031351"/>, <cite idref="PUB00022677"/>], and both are type 1 membrane proteins that include an approximately 200-aa extracellular von Willebrand factor A (VWA) domain with a metal ion-dependent adhesion site (MIDAS) motif [<cite idref="PUB00022677"/>].</p><p>This group represents anthrax toxin receptor 2.</p>