Amanita phalloide is one of the most toxic mushrooms know to man, giving the mushroom the name of “death cap.” Although mushroom poisoning does exist in the United States, European countries experience 50 to 100 fatalities a year caused by Amanita phalloides alone. The toxins released from this mushroom act mainly on the liver, and to a lesser degree on the kidneys, and are responsible for various gastrointestinal effects.

Research shows that alpha-amanitin acts as an inhibitor to the polymerase II and interferes with the mRNA synthesis. [6] The alpha-amanitin is a small, circular peptide that attacks the RNA polymerase and binds to the back-side of the enzyme. This is away from both the active site and from the site where the DNA and the RNA bind. The toxin denies the polymerase the ability to move freely, which is necessary to performing the steps of transcription.

By blocking these necessary moving motions, the polymerase cannot perform transcription, therefore killing the cell and denying any replication. This causes cellular necrosis and prevents cellular reproduction, especially in the liver, kidneys, and gastrointestinal organs.