3'-immature tRNATrp is required for ribosome inactivation by gelonin, a plant RNA N-glycosidase
1995
Brigotti, M. | Carnicelli, D. | Alvergna, P. | Pallanca, A. | Lorenzetti, R. | Denaro, M. | Sperti, S. | Montanaro, L.
Inactivation of ribosomes by gelonin, a ribosome-inactivating protein with RNA N-glycosidase activity on 28 S rRNA, requires macromolecular cofactors present in post-ribosomal supernatants. One of these cofactors has been purified from a rat liver extract and identified as an RNA about 70 nt long which in sequence analysis shows a high level of similarity with mammalian (bovine) tRNATrp. The pattern of the sequencing gel is consistent with the co-existence in the preparation of two 3'-immature tRNATrp species, missing only A75, or both A75 and C74. In the presence of ATP, CTP and tRNA nucleotidyltransferase, the gelonin-stimulating RNA is a good acceptor of tryptophan. An oligodeoxynucleotide complementary to positions 55 to 72 of mammalian (bovine) tRNATrp hybridizes with the gelonin-stimulating RNA as demonstrated by gel mobility shift and ribonuclease H digestion. The oligodeoxynucleotide-directed ribonuclease H treatment also abolishes the gelonin-promoting activity of crude preparations of RNA, giving strong evidence that the only active RNA is a tRNATrp-like molecule.
显示更多 [+] 显示较少 [-]