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Nucleotides U28–A42 and A37 in unmodified yeast tRNA Trp as negative identity elements for bovine tryptophanyl‐tRNA synthetase
Author(s) -
Carnicelli Domenica,
Brigotti Maurizio,
Rizzi Simona,
Keith Gérard,
Montanaro Lucio,
Sperti Simonetta
Publication year - 2001
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)02261-x
Subject(s) - yeast , transfer rna , aminoacylation , biochemistry , biology , saccharomyces cerevisiae , enzyme , nucleotide , aminoacyl trna synthetase , rna , gene
Wild‐type bovine and yeast tRNA Trp are efficiently aminoacylated by tryptophanyl‐tRNA synthetase both from beef and from yeast. Upon loss of modified bases in the synthetic transcripts, mammalian tRNA Trp retains the double recognition by the two synthetases, while yeast tRNA Trp 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 tRNA Trp by the beef enzyme, a negative combination apparently emerges in the synthetic transcript after unmasking of U28 by loss of pseudourydilation.