The invariance of NMR residual dipolar couplings (RDCs) in denatured forms of staphylococcal nuclease to changes in denaturant concentration or amino acid sequence has previously been attributed to the robustness of long-range structure in the denatured state. Here we compare RDCs of the wild-type nuclease with those of a fragment that retains a folded OB-fold subdomain structure despite missing the last 47 of 149 residues. The RDCs of the intact protein and of the truncation fragment are substantially different under conditions that favor folded structure. By contrast, there is a strong correlation between the RDCs of the full-length protein and the fragment under denaturing conditions (6 M urea). The RDCs of the folded and unfolded forms of the proteins are uncorrelated. Our results suggest that RDCs are more sensitive to structural changes in folded than unfolded proteins. We propose that the greater susceptibility of RDCs in folded states is a consequence of the close packing of the polypeptide chain under native conditions. By contrast, the invariance of RDCs in denatured states is more consistent with a disruption of cooperative structure than with the retention of a unique long-range folding topology.
Measurement of 1Hâ??15N and 1Hâ??13C residual dipolar couplings in nucleic acids from TROSY intensities
Measurement of 1Hâ??15N and 1Hâ??13C residual dipolar couplings in nucleic acids from TROSY intensities
Abstract Analogous to the recently introduced ARTSY method for measurement of one-bond 1Hâ??15N residual dipolar couplings (RDCs) in large perdeuterated proteins, we introduce methods for measurement of base 13Câ??1H and 15Nâ??1H RDCs in protonated nucleic acids. Measurements are based on quantitative analysis of intensities in 1Hâ??15N and 13Câ??1H TROSY-HSQC spectra, and are illustrated for a 71-nucleotide adenine riboswitch. Results compare favorably with those of conventional...
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09-30-2011 08:01 PM
Residual dipolar couplings: are multiple independent alignments always possible?
Residual dipolar couplings: are multiple independent alignments always possible?
Abstract RDCs for the 14 kDa protein hen egg-white lysozyme (HEWL) have been measured in eight different alignment media. The elongated shape and strongly positively charged surface of HEWL appear to limit the protein to four main alignment orientations. Furthermore, low levels of alignment and the proteinâ??s interaction with some alignment media increases the experimental error. Together with heterogeneity across the alignment media arising from constraints on temperature, pH and ionic strength for some...
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12-26-2010 04:43 AM
[NMR paper] Refined NMR structure of alpha-sarcin by 15N-1H residual dipolar couplings.
Refined NMR structure of alpha-sarcin by 15N-1H residual dipolar couplings.
Related Articles Refined NMR structure of alpha-sarcin by 15N-1H residual dipolar couplings.
Eur Biophys J. 2005 Nov;34(8):1057-65
Authors: García-Mayoral MF, Pantoja-Uceda D, Santoro J, Martínez del Pozo A, Gavilanes JG, Rico M, Bruix M
(15)N-(1)H residual dipolar couplings (RDC) have been used as additional restraints to refine the solution structure of the ribotoxin alpha-sarcin. The RDC values were obtained by partial alignment of alpha-sarcin in the binary mixture...
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11-25-2010 08:21 PM
[NMR paper] Residual dipolar couplings in NMR structure analysis.
Residual dipolar couplings in NMR structure analysis.
Related Articles Residual dipolar couplings in NMR structure analysis.
Annu Rev Biophys Biomol Struct. 2004;33:387-413
Authors: Lipsitz RS, Tjandra N
Residual dipolar couplings (RDCs) have recently emerged as a new tool in nuclear magnetic resonance (NMR) with which to study macromolecular structure and function in a solution environment. RDCs are complementary to the more conventional use of NOEs to provide structural information. While NOEs are local-distance restraints, RDCs provide...
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11-24-2010 09:25 PM
[NMR paper] Residual dipolar couplings: synergy between NMR and structural genomics.
Residual dipolar couplings: synergy between NMR and structural genomics.
Related Articles Residual dipolar couplings: synergy between NMR and structural genomics.
J Biomol NMR. 2002 Jan;22(1):1-8
Authors: Al-Hashimi HM, Patel DJ
Structural genomics is on a quest for the structure and function of a significant fraction of gene products. Current efforts are focusing on structure determination of single-domain proteins, which can readily be targeted by X-ray crystallography, NMR spectroscopy and computational homology modeling. However,...
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11-24-2010 08:49 PM
[NMR paper] Protein structural motif recognition via NMR residual dipolar couplings.
Protein structural motif recognition via NMR residual dipolar couplings.
Related Articles Protein structural motif recognition via NMR residual dipolar couplings.
J Am Chem Soc. 2001 Feb 14;123(6):1222-9
Authors: Andrec M, Du P, Levy RM
NMR residual dipolar couplings have great potential to provide rapid structural information for proteins in the solution state. This information even at low resolution may be used to advantage in proteomics projects that seek to annotate large numbers of gene products for entire genomes. In this paper, we...
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11-19-2010 08:32 PM
Facile measurement of 1Hâ??15N residual dipolar couplings in larger perdeuterated pro
Abstract We present a simple method, ARTSY, for extracting 1JNH couplings and 1Hâ??15N RDCs from an interleaved set of two-dimensional 1Hâ??15N TROSY-HSQC spectra, based on the principle of quantitative J correlation. The primary advantage of the ARTSY method over other methods is the ability to measure couplings without scaling peak positions or altering the narrow line widths characteristic of TROSY spectra. Accuracy of the method is demonstrated for the model system GB3. Application to the catalytic core domain of HIV integrase, a 36 kDa homodimer with unfavorable spectral...
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08-14-2010 04:19 AM
Theoretical framework for NMR residual dipolar couplings in unfolded proteins
Theoretical framework for NMR residual dipolar couplings in unfolded proteins
O. I. Obolensky, Kai Schlepckow, Harald Schwalbe and A. V. Solov’yov
Journal of Biomolecular NMR; 2007; 39(1) pp 1-16
Abstract:
A theoretical framework for the prediction of nuclear magnetic resonance (NMR) residual dipolar couplings (RDCs) in unfolded proteins under weakly aligning conditions is presented. The unfolded polypeptide chain is modeled as a random flight chain while the alignment medium is represented by a set of regularly arranged obstacles. For the case of bicelles oriented perpendicular to...