title: The effect of ribosome-inactivating proteins on the ribosome from the hyperthermophilic archaeon Sulfolobus solfataricus.
abstract: Protein synthesis in the thermoacidophilic archaeon Sulfolobus solfataricus (Ss) was inhibited by polynucleotide:adenosine glycosylase activity of some type 1 ribosome-inactivating proteins (RIP). The target of RIP was S. solfataricus rRNA that was depurinated thus producing inactive ribosomes. The amount of RIP required to half-inactivated Ss-ribosomes was comparable to that needed for eubacterial ribosomes, but two orders of magnitude higher than that required for mammalian ribosomes. In addition, RIP treated Ss-ribosomes were also less efficient in stimulating the ribosome dependent GTPase activity of the S. solfataricus elongation factor 2 (SsEF-2) thus suggesting that the inhibition of protein synthesis was probably due to the lack of the interaction between depurinated Ss-ribosomes and SsEF-2. Since SsEF-2 protects Ss-ribosomes against RIP activity it can be hypothesised that also on Ss-ribosomes the sites of interaction for the translocation factor 2 and the RIP are topographically close.
authors.affiliation: Dipartimento di Biochimica e Biotecnologie Mediche, Università di Napoli Federico II, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Raimo
authors.forename: A
authors.initials: A
authors.lastname: Arcucci
authors.forename: L
authors.initials: L
authors.lastname: Barbieri
authors.forename: P
authors.initials: P
authors.lastname: Valbonesi
authors.forename: M
authors.initials: M
authors.lastname: Masullo
authors.forename: F
authors.initials: F
authors.lastname: Stirpe
authors.forename: V
authors.initials: V
authors.lastname: Bocchini
mesh_terms: D019843:Archaeal Proteins / Q000096:biosynthesis; D006023:Glycoproteins / Q000494:pharmacology; D000922:Immunotoxins; D009699:N-Glycosyl Hydrolases; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors / Q000378:metabolism; D010940:Plant Proteins / Q000494:pharmacology*; D011072:Poly U / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D012335:RNA, Ribosomal / Q000378:metabolism; D054789:Ribosome Inactivating Proteins, Type 1; D054790:Ribosome Inactivating Proteins, Type 2; D012270:Ribosomes / Q000187:drug effects* / Q000378:metabolism*; D000076985:Saporins; D016944:Sulfolobus / Q000187:drug effects* / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D019843:Archaeal Proteins; D006023:Glycoproteins; D000922:Immunotoxins; D020652:Peptide Elongation Factor 2; D010445:Peptide Elongation Factors; D010940:Plant Proteins; D011500:Protein Synthesis Inhibitors; D012335:RNA, Ribosomal; D054789:Ribosome Inactivating Proteins, Type 1; D054790:Ribosome Inactivating Proteins, Type 2; C057422:trichokirin protein, Trichosanthes kirilowii; D011072:Poly U; D009699:N-Glycosyl Hydrolases; D000076985:Saporins; C024275:pokeweed antiviral protein