Assignments of /sup 31/P NMR resonances in oligodeoxyribonucleotides: origin of sequence-specific variations in the deoxyribose phosphate backbone conformation and the /sup 31/P chemical shifts of double-helical nucleic acids
It is now possible to unambiguously assign all 31P resonances in the 31P NMR spectra of oligonucleotides by either two-dimensional NMR techniques or site-specific 17O labeling of the phosphoryl groups. Assignment of 31P signals in tetradecamer duplexes, (dTGTGAGCGCTCACA)2, (dTAT-GAGCGCTCATA)2, (dTCTGAGCGCTCAGA)2, and (dTGTGTGCGCACACA)2, and the dodecamer duplex d(CGTGAATTCGCG)2 containing one base-pair mismatch, combined with additional assignments in the literature, has allowed an analysis of the origin of the sequence-specific variation in 31P chemical shifts of DNA. The 31P chemical shifts of duplex B-DNA phosphates correlate reasonably well with some aspects of the Dickerson/Calladine sum function for variation in the helical twist of the oligonucleotides. Correlations between experimentally measured P-O and C-O torsional angles and results from molecular mechanics energy minimization calculations show that these results are consistent with the hypothesis that sequence-specific variations in 31P chemical shifts are attributable to sequence-specific changes in the deoxyribose phosphate backbone. The major structural variation responsible for these 31P shift perturbations appears to be P-O and C-O backbone torsional angles which respond to changes in the local helical structure. Furthermore, 31P chemical shifts and JH3'-P coupling constants both indicate that these backbone torsional angle variations are more permissive at the ends of the double helix than in the middle. Thus 31P NMR spectroscopy and molecular mechanics energy minimization calculations appear to be able to support sequence-specific structural variations along the backbone of the DNA in solution.
- Research Organization:
- Purdue Univ., West Lafayette, IN (USA)
- OSTI ID:
- 6354314
- Journal Information:
- Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 27:19; ISSN BICHA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CARBOHYDRATES
CHEMICAL SHIFT
CONFIGURATION
DAYS LIVING RADIOISOTOPES
DEOXYRIBOSE
DNA
DNA MISMATCH
HELICAL CONFIGURATION
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MONOSACCHARIDES
NMR SPECTRA
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUCLEIC ACIDS
ODD-ODD NUCLEI
OLIGONUCLEOTIDES
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PENTOSES
PHOSPHATES
PHOSPHORUS 32
PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
RADIOISOTOPES
RESONANCE
SACCHARIDES
SPECTRA
TRACER TECHNIQUES