Nucleotides U28-A42 and A37 in unmodified yeast tRNATrpas negative identity elements for bovine tryptophanyl-tRNA synthetase

Autor: Domenica Carnicelli, Maurizio Brigotti, Simona Rizzi, Lucio Montanaro, Gérard Keith, Simonetta Sperti
Rok vydání: 2001
Předmět:
Zdroj: FEBS Letters. 492:238-241
ISSN: 0014-5793
DOI: 10.1016/s0014-5793(01)02261-x
Popis: Wild-type bovine and yeast tRNATrp are efficiently aminoacylated by tryptophanyl-tRNA synthetase both from beef and from yeast. Upon loss of modified bases in the synthetic transcripts, mammalian tRNATrp retains the double recognition by the two synthetases, while yeast tRNATrp loses its substrate properties for the bovine enzyme and is recognised only by the cognate synthetase. By testing chimeric bovine–yeast transcripts with tryptophanyl-tRNA synthetase purified from beef pancreas, the nucleotides responsible for the loss of charging of the synthetic yeast transcript have been localised in the anticodon arm. A complete loss of charging akin to that observed with the yeast transcript requires substitution in the bovine backbone of G37 in the anticodon loop with yeast A37 and of C28–G42 in the anticodon stem with yeast U28–A42. Since A37 does not prevent aminoacylation of the wild-type yeast tRNATrp by the beef enzyme, a negative combination apparently emerges in the synthetic transcript after unmasking of U28 by loss of pseudourydilation.
Databáze: OpenAIRE
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