Abstract
Imino 1H-15N residual dipolar couplings (RDCs) provide additional structural information that complements standard 1H-1H NOEs leading to improvements in both the local and global structure of RNAs. Here, we report measurement of imino 1H-1H RDCs for the Iron Responsive Element (IRE) RNA and native E. coli tRNAVal using a BEST-Jcomp-HMQC2 experiment. 1H-1H RDCs are observed between the imino protons in G-U wobble base pairs and between imino protons on neighboring base pairs in both RNAs. These imino 1H- 1H RDCs complement standard 1H-15N RDCs because the 1H-1H vectors generally point along the helical axis, roughly perpendicular to 1H- 15N RDCs. The use of longitudinal relaxation enhancement increased the signal-to-noise of the spectra by ∼3.5-fold over the standard experiment. The ability to measure imino 1H- 1H RDCs offers a new restraint, which can be used in NMR domain orientation and structural studies of RNAs.
Original language | English |
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Pages (from-to) | 121-129 |
Number of pages | 9 |
Journal | Journal of Biomolecular NMR |
Volume | 43 |
Issue number | 2 |
DOIs | |
State | Published - 2009 |
Keywords
- Iron responsive element RNA
- Partial alignment
- RNA structure
- Residual dipolar couplings
- tRNA