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Metzger, Armin U. ; Heckl, Martha ; Willbold, Dieter ; Breitschopf, Kristin ; RhajBandhary, Uttam L. ; Rösch, Paul ; Gross, Hans Joachim:
Structural studies on tRNA acceptor stem microhelices : exchange of the discriminator base A73 for G in human tRNAᴸᵉᵘ switches the acceptor specificity from leucine to serine possibly by decreasing the stability of the terminal G1-C72 base pair.
In: Nucleic Acids Research.
Bd. 25
(1997)
Heft 22
.
- S. 4551-4556.
ISSN 1362-4962
DOI: https://doi.org/10.1093/nar/25.22.4551
Abstract
Correct recognition of transfer RNAs (tRNAs) by aminoacyl-tRNA synthetases (aaRS) is crucial to the maintenance of translational fidelity. The discriminator base A73 in human tRNALeuis critical for its specific recognition by the aaRS. Exchanging A73 for G abolishes leucine acceptance and converts it into a serine acceptor in vitro . Two RNA microhelices of 24 nt length that correspond to the tRNALeuacceptor stem and differ only in the discriminator base were synthesized: a wild-type tRNALeumicrohelix, where nt 21 corresponds to the discriminator base position 73, and an A21G mutant microhelix. To investigate whether different identities of both tRNAs are caused by conformational differences, NMR and UV melting experiments were performed on both microhelices. Two-dimentional NOESY spectra showed both microhelices to exhibit the same overall conformation at their 3'-CCA ends. Thermodynamic analysis and melting behaviour of the base-paired imino protons observed by NMR spectroscopy suggest that the A21G (A73G in tRNA) exchange results in a decrease of melting transition cooperativity and a destabilization of the terminal G1-C20 (G1-C72 in tRNA) base pair. Furthermore, the fact that this 3'-terminal imino proton is more solvent-exposed at physiological temperature might be another indication for the importance of the stability of the terminal base pair for specific tRNA recognition.
Weitere Angaben
| Publikationsform: | Artikel in einer Zeitschrift |
|---|---|
| Begutachteter Beitrag: | Ja |
| Institutionen der Universität: | Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Ehemalige Professoren > Lehrstuhl Biopolymere - Univ.-Prof. Dr. Paul Rösch Fakultäten Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Ehemalige Professoren Fakultäten > Fakultät für Biologie, Chemie und Geowissenschaften > Fachgruppe Chemie > Lehrstuhl Biochemie mit Schwerpunkt Biophysikalische Chemie |
| Titel an der UBT entstanden: | Ja |
| Themengebiete aus DDC: | 500 Naturwissenschaften und Mathematik > 540 Chemie 500 Naturwissenschaften und Mathematik > 570 Biowissenschaften; Biologie |
| Eingestellt am: | 15 Jan 2019 13:31 |
| Letzte Änderung: | 31 Mär 2022 13:43 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/46904 |