Anthrax edema factor

Function

Anthrax edema factor (EF) or calmodulin-sensitive adenylate cyclase is an enzyme which is part of the Bacillus anthracis anthrax toxin. The full anthrax toxin is composed of -

• A cell-binding protein Anthrax protective antigen
  
• Anthrax Lethal Factor
  
• and anthrax edema factor.
  

The EF is a calcium- and calmodulin-dependent adenylate cyclase. The binding of calmodulin to EF changes it from its non-active form to the active one.^[1] See also Toxins.

Disease

The anthrax disease is caused by the invasion of cells by the bacteria followed by increasing the cellular level of cAMP thus upsetting water homeostasis and causing disruption of signaling pathways.

Structural highlights

• EF trimer with 3 calmodulin molecules.
• ADP derivative/Yt+3 binding site of EF. Water molecules are shown as red spheres.
• Ca+2 binding site of calmodulin (PDB code 1pk0).^[2]

3D structures of anthrax edema factor

Anthrax edema factor 3D structures