Measurement of imino 1H-1H residual dipolar couplings in RNA.

ABSTRACT: Imino (1)H-(15)N residual dipolar couplings (RDCs) provide additional structural information that complements standard (1)H-(1)H NOEs leading to improvements in both the local and global structure of RNAs. Here, we report measurement of imino (1)H-(1)H RDCs for the Iron Responsive Element (IRE) RNA and native E. coli tRNA(Val) using a BEST-Jcomp-HMQC2 experiment. (1)H-(1)H 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 (1)H-(1)H RDCs complement standard (1)H-(15)N RDCs because the (1)H-(1)H vectors generally point along the helical axis, roughly perpendicular to (1)H-(15)N RDCs. The use of longitudinal relaxation enhancement increased the signal-to-noise of the spectra by ~3.5-fold over the

SUBMITTER: Latham MP 

PROVIDER: S-EPMC2846714 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature