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Insight into the CSA tensors of nucleobase carbons in RNA polynucleotides from solution measurements of residual CSA: towards new long-range orientational constraints.

Publication ,  Journal Article
Hansen, AL; Al-Hashimi, HM
Published in: J Magn Reson
April 2006

Using residual chemical shift anisotropies (RCSAs) measured in a weakly aligned stem-loop RNA, we examined the carbon chemical shift anisotropy (CSA) tensors of nucleobase adenine C2, pyrimidine C5 and C6, and purine C8. The differences between the measured RCSAs and the values back-calculated using three nucleobase carbon CSA sets [D. Stueber, D.M. Grant, 13C and 15N chemical shift tensors in adenosine, guanosine dihydrate, 2'-deoxythymidine, and cytidine, J. Am. Chem. Soc. 124 (2002) 10539-10551; D. Sitkoff, D.A. Case, Theories of chemical shift anisotropies in proteins and nucleic acids, Prog. NMR Spectrosc. 32 (1998) 165-190; R. Fiala, J. Czernek, V. Sklenar, Transverse relaxation optimized triple-resonance NMR experiments for nucleic acids, J. Biomol. NMR 16 (2000) 291-302] reported previously for mononucleotides (1.4 Hz) is significantly smaller than the predicted RCSA range (-10-10 Hz) but remains larger than the RCSA measurement uncertainty (0.8 Hz). Fitting of the traceless principal CSA values to the measured RCSAs using a grid search procedure yields a cytosine C5 CSA magnitude (CSAa=(3/2.(delta11(2)+delta22(2)+delta33(2)))1/2=173+/-21 ppm), which is significantly higher than the reported mononucleotide values (131-138 ppm) and a guanine C8 CSAa (148+/-13 ppm) that is in very good agreement with the mononucleotide value reported by solid-state NMR [134 ppm, D. Stueber, D.M. Grant, 13C and (15)N chemical shift tensors in adenosine, guanosine dihydrate, 2'-deoxythymidine, and cytidine, J. Am. Chem. Soc. 124 (2002) 10539-10551]. Owing to a unique sensitivity to directions normal to the base plane, the RCSAs can be translated into useful long-range orientational constraints for RNA structure determination even after allowing for substantial uncertainty in the nucleobase carbon CSA tensors.

Duke Scholars

Published In

J Magn Reson

DOI

ISSN

1090-7807

Publication Date

April 2006

Volume

179

Issue

2

Start / End Page

299 / 307

Location

United States

Related Subject Headings

  • Solutions
  • RNA
  • Pyrimidines
  • Purines
  • Polynucleotides
  • Nuclear Magnetic Resonance, Biomolecular
  • Nitrogen Isotopes
  • Molecular Structure
  • Molecular Conformation
  • Carbon Isotopes
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Journal cover image

Published In

J Magn Reson

DOI

ISSN

1090-7807

Publication Date

April 2006

Volume

179

Issue

2

Start / End Page

299 / 307

Location

United States

Related Subject Headings

  • Solutions
  • RNA
  • Pyrimidines
  • Purines
  • Polynucleotides
  • Nuclear Magnetic Resonance, Biomolecular
  • Nitrogen Isotopes
  • Molecular Structure
  • Molecular Conformation
  • Carbon Isotopes