The effect of ribosome-inactivating proteins on the ribosome from the hyperthermophilic archaeon Sulfolobus solfataricus.
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.
Raimo
G
G
Dipartimento di Biochimica e Biotecnologie Mediche, Università di Napoli Federico II, Italy.
Arcucci
A
A
Barbieri
L
L
Valbonesi
P
P
Masullo
M
M
Stirpe
F
F
Bocchini
V
V
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
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