Ribosome-inactivating protein of type 1, inhibits protein synthesis in animal cells. Inhibits cell-free translation in rabbit reticulocyte lysate system with an IC(50) of 0.17 nM. Endohydrolysis of the N-glycosidic bond at one specific adenosine on the 28S rRNA. Monomer. Belongs to the ribosome-inactivating protein family. Type 1 RIP subfamily.