Alpha-aminitin is found in the “Death Cap” mushroom. The general mechanism of alpha-amanitin is to block translocation in the elongating Polymerase II. Alpha-amanitin is the most potent inhibitor of the Polymerase II enzyme, binding beneath a “bridge helix” located on the funnel and cleft regions of Rpb1. Alpha-amanitin binds bridge helix residue Glu822 and Gln768, which binds to His816, a bridge helix residue. There are also binding sites for alpha-amanitin adjacent to Rpb1. All of these binding sites stop the bridge helix’s ability to move into a bent conformation. This severely reduces translocation (about 1000-fold), which shuts down transcription. If consumed the organism will not be able to perform transcription and will cease to be viable in a very short period of time (4).