Studying base pair open–close kinetics of tRNA Leu by TROSY-based proton exchange NMR spectroscopy

Abstract

The millisecond conformational flexibility is functionally important for nucleic acids and can be studied through probing the base pair open–close kinetics by proton exchange nuclear magnetic resonance (NMR) spectroscopy. Here, the traditional imino proton exchange NMR experiments were modified with transverse relaxation optimized spectroscopy and were applied to accurately measure imino proton exchange rates of all base pairs in Escherichia coli tRNA Leu (CAG), and their dependence on magnesium ion concentration. Finally, we correlated millisecond conformational flexibility with aminoacylation of tRNA Leu and proposed that the flexibility of the acceptor stem and the core region might contribute to aminoacylation of tRNA Leu.