title: Rotational diffusion tensor of nucleic acids from 13C NMR relaxation.
abstract: Rotational diffusion properties have been derived for the DNA dodecamer d(CGCGAATTCGCG)(2) from (13)C R(1rho) and R(1) measurements on the C(1'), C(3'), and C(4') carbons in samples uniformly enriched in (13)C. The narrow range of C-H bond vector orientations relative to the DNA axis make the analysis particularly sensitive to small structural deviations. As a result, the R(1rho)/R(1) ratios are found to fit poorly to the crystal structures of this dodecamer, but well to a recent solution NMR structure, determined in liquid crystalline media, even though globally the structures are quite similar. A fit of the R(1rho)/R(1) ratios to the solution structure is optimal for an axially symmetric rotational diffusion model, with a diffusion anisotropy, D(\|)/D(perpendicular), of 2.1+/-0.4, and an overall rotational correlation time, (2D(\|)+4D(perpendicular))(-1), of 3.35 ns at 35 degrees C in D(2)O, in excellent agreement with values obtained from hydrodynamic modeling.
authors.affiliation: Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892-0520, U.S.A.
authors.forename: Jerome
authors.initials: J
authors.lastname: Boisbouvier
authors.forename: Zhengrong
authors.initials: Z
authors.lastname: Wu
authors.forename: Arika
authors.initials: A
authors.lastname: Ono
authors.forename: Masatsune
authors.initials: M
authors.lastname: Kainosho
authors.forename: Ad
authors.initials: A
authors.lastname: Bax
mesh_terms: D002247:Carbon Isotopes; D009682:Magnetic Resonance Spectroscopy; D009690:Nucleic Acid Conformation; D009696:Nucleic Acids / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D009696:Nucleic Acids