Polynucleotide: adenosine glycosidase activity of saporin-L1: effect on DNA, RNA and poly(A).

The Cytotoxic Activity of Ribosome-inactivating Protein Saporin-6 Is Attributed to Its rRNA N-Glycosidase and Internucleosomal DNA

Saporin-6 produced by the plant Saponaria officinalis belongs to the family of single chain ribosome-inactivating proteins. It potently inhibits protein synthesis in eukaryotic cells, by cleaving the N-glycosidic bond of a specific adenine in 28 S rRNA, which results in the cell death. Saporin-6 has also been shown to be active on DNA and induces apoptosis. In the current study, we have investi...

The cytotoxic activity of ribosome-inactivating protein saporin-6 is attributed to its rRNA N-glycosidase and internucleosomal DNA fragmentation activities.

Saporin-6 produced by the plant Saponaria officinalis belongs to the family of single chain ribosome-inactivating proteins. It potently inhibits protein synthesis in eukaryotic cells, by cleaving the N-glycosidic bond of a specific adenine in 28 S rRNA, which results in the cell death. Saporin-6 has also been shown to be active on DNA and induces apoptosis. In the current study, we have investi...

The cytotoxic activity of ribosome-inactivating protein saporin-6 is attributed to rRNA N-glycosidase and internucleosomal DNA fragmentation

Transition state analogues in structures of ricin and saporin ribosome-inactivating proteins.

Ricin A-chain (RTA) and saporin-L1 (SAP) catalyze adenosine depurination of 28S rRNA to inhibit protein synthesis and cause cell death. We present the crystal structures of RTA and SAP in complex with transition state analogue inhibitors. These tight-binding inhibitors mimic the sarcin-ricin recognition loop of 28S rRNA and the dissociative ribocation transition state established for RTA cataly...

Polynucleotide:adenosine glycosidase activity of ribosome-inactivating proteins: effect on DNA, RNA and poly(A).

Ribosome-inactivating proteins (RIP) are a family of plant enzymes for which a unique activity was determined: rRNAN-glycosidase at a specific universally conserved position, A4324in the case of rat ribosomes. Recently we have shown that the RIP from Saponaria officinalis have a much wider substrate specificity: they are actually polynucleotide:adenosine glycosidases. Here we extend studies on ...