MD simulations of anthrax edema factor: calmodulin complexes with mutations in the edema factor "switch a" region and docking of 3'-deoxy ATP into the adenylyl cyclase active site of wild-type and mutant edema factor variants.

Bacillus anthracis, a spore-forming infectious bacterium, produces an exotoxin, called the edema factor (EF), that functions in part by disrupting internal signalling pathways. When complexed with human host cell calmodulin (CaM), EF becomes an active adenylyl cyclase, producing the internal signal substance cyclic-AMP in an uncontrolled fashion. Recently, the crystal structures for uncomplexed EF and EF:CaM complexes in the presence and absence of a substrate analog (3'-deoxy-ATP), were reported.