Anthrax Structure
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The anthrax toxin is made up of three different proteins. The first protein, the PA constitutes what is known as the carrier of the toxin. It is the PA that binds to the cell at the Anthrax toxin receptor (ATR). Once bound to this receptor, the protein undergoes a major conformational change. It is after this conformational change whenthe two other proteinsbind. The next protein of the Anthrax system is the edema factor (EF). The final protein is known as the LF and was recently crystallized (Pannifer et all, 2001) and thus a mechanism was proposed. Although all three proteins enter the cell's cytoplasm, it is the EF and LF that cause the cell toxicity.

Background
Anthrax Structure
MAPK Structure
Anthrax Pathway
MAPK Cascade
When the PA and the LF bind, what is formed is known as the LeTx. Even without the addition of EF, the LeTx can cause rapid death in animals. The LeTx, once inside the cell, splits apart and thus releases the LF. LF is a four-domain protein. It is on the first domain where the LF binds to the PA. The second domain is relatively inactive, yet may contain a site for the binding of NAD. Domain three is the most likely place for the active site of LF. It is this site that interferes with the MAPKK. Domain four is the catalytic center of the protein, as it binds tightly to a Zinc cation(Pannifer et all, 2001).
Lethal Factor and MAPK
The Future
References
Figure 2--The four domain protein of LF
Figure ?--The Structure of PA