Ribosome-inactivating protein (IPR001574)

Short name: Ribosome_inactivat_prot

Overlapping homologous superfamilies

Family relationships


A number of bacterial and plant toxins act by inhibiting protein synthesis in eukaryotic cells. The toxins of the shiga and ricin family inactivate 60S ribosomal subunits by an N-glycosidic cleavage which releases a specific adenine base from the sugar-phosphate backbone of 28S rRNA [PMID: 3276522, PMID: 2714255, PMID: 1742358]. Members of the family include shiga and shiga-like toxins, and type I (e.g. trichosanthin and luffin) and type II (e.g. ricin, agglutinin and abrin) ribosome inactivating proteins (RIPs). All these toxins are structurally related. RIPs have been of considerable interest because of their potential use, conjugated with monoclonal antibodies, as immunotoxins to treat cancers. Further, trichosanthin has been shown to have potent activity against HIV-1-infected T cells and macrophages [PMID: 8066085]. Elucidation of the structure-function relationships of RIPs has therefore become a major research effort. It is now known that RIPs are structurally related. A conserved glutamic residue has been implicated in the catalytic mechanism [PMID: 3357883]; this lies near a conserved arginine, which also plays a role in catalysis [PMID: 8411176].

GO terms

Biological Process

GO:0017148 negative regulation of translation

Molecular Function

GO:0030598 rRNA N-glycosylase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.