Ribosome-inactivating proteins (RIP) are a family of plant enzymes for which a unique activity was determined: rRMA N-glycosidase at a specific universally conserved position, A4324 in 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 substrate specificity to most known RIP: 52 purified proteins, both type 1 (single-chain) and type 2 (two chain, an enzymatic chain and a lectin chain) were examined for adenine release on various substrates including RNAs from different sources, DNA, and poly(A). All RIP depurinated extensively DNA and some released adenine from all adenine-containing polynucleotides tested. From experimental evidence the entire class of plant proteins, up to now called ribosome-inactivating proteins, may be classified as polynucleotide:adenosine glycosidases. The newly identified substrates may be implicated in the biological role(s) of RIP.
Barbieri, L., Valbonesi, P., Bonora, E., Gorini, P., Bolognesi, A., Stirpe, F. (1997). Polynucleotide:adenosine glycosidase activity of ribosome-inactivating proteins: Effect on DNA, RNA and poly(A). NUCLEIC ACIDS RESEARCH, 25(3), 518-522 [10.1093/nar/25.3.518].
Polynucleotide:adenosine glycosidase activity of ribosome-inactivating proteins: Effect on DNA, RNA and poly(A)
Barbieri L.;Valbonesi P.;Bonora E.;Bolognesi A.;Stirpe F.
1997
Abstract
Ribosome-inactivating proteins (RIP) are a family of plant enzymes for which a unique activity was determined: rRMA N-glycosidase at a specific universally conserved position, A4324 in 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 substrate specificity to most known RIP: 52 purified proteins, both type 1 (single-chain) and type 2 (two chain, an enzymatic chain and a lectin chain) were examined for adenine release on various substrates including RNAs from different sources, DNA, and poly(A). All RIP depurinated extensively DNA and some released adenine from all adenine-containing polynucleotides tested. From experimental evidence the entire class of plant proteins, up to now called ribosome-inactivating proteins, may be classified as polynucleotide:adenosine glycosidases. The newly identified substrates may be implicated in the biological role(s) of RIP.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
