basic protein 150 aa, MW 16 kDa; isolated from aspergillus giganteus; sequence similarity with ribonucleases such as RIBONUCLEASE T1; 85% identity with restrictocin; a ribotoxin cleaving the phosphodiester bond on the 3' side of G4325 in the alpha-sarcin/ricin domain of rat 28S RIBOSOMAL RNA; sometimes called a ribosome-inactivating protein but falls outside the normal definition of plant RIP that de-adenylate rRNA
