Characterization of ricin toxin family members from Ricinus communis.

Ricin inhibits translation by removal of a specific adenine from 28S RNA. The Ricinus communis genome encodes seven full-length ricin family members. All encoded proteins have the ability of hydrolyzing adenine in 28S rRNA. As expected, these proteins also inhibited an in vitro transcription/translation system. These data show that the ricin gene family contains at least seven members that have the ability to inhibit translation and that may contribute to the toxicity of R. communis.