PROTON NMR-STUDIES OF MANGANESE ION-BINDING TO TRANSFER-RNA-DERIVED ACCEPTOR ARM DUPLEXES

Several RNA duplexes corresponding to the acceptor arms of different t RNAs have been analyzed with respect to their divalent metal ion bindi ng capability by means of proton NMR spectroscopy using paramagnetic M n2+ ions as probes. In particular, the role of GU wobble base pairs ha s been analyzed with reference to their potential for creating metal i on binding sites. It is shown that both the structural modifications i nduced by GU pairs in the A-RNA geometry and the sequence context seem to affect the metal ion binding capabilities.