Residual heteronuclear dipolar couplings obtained from partially oriented protein samples can provide unique NMR constraints for protein structure determination. However, partial orientation of protein samples also causes severe 1H line broadening resulting from residual 1H-1H dipolar couplings. In this communication we show that band-selective 1H homonuclear decoupling during data acquisition ...

Measurement of 1H-1H dipolar couplings in macromolecules, weakly oriented by a dilute liquid crystalline medium, is generally limited to the largest such interactions. By removing dipolar couplings to nearest neighbors, either by decoupling, deuteration, or both, more remote interactions become accessible. The approach is demonstrated for measurement of amide-amide interactions in the proteins ...

The computational tools necessary for making use of (1)H-(1)H dipolar couplings in macromolecular structure refinement are presented. Potentials are described for direct refinement against (1)H-(1)H dipolar couplings of known sign as well as of unknown sign. In addition, a multiple potential is developed for prochiral protons whose stereospecific assignments are unknown. The utility of direct (...

Residual dipolar couplings are useful global structural restraints. The dipolar couplings define the orientation of a vector with respect to the alignment tensor. Although the size of the alignment tensor can be derived from the distribution of the experimental dipolar couplings, its orientation with respect to the coordinate system of the molecule is unknown at the beginning of structure deter...

Residual dipolar couplings are being increasingly used as structural constraints for NMR studies of biomolecules. A problem arises when dipolar coupling contributions are larger than scalar contributions for a given spin pair, as is commonly observed in solid state NMR studies, in that signs of dipolar couplings cannot easily be determined. Here the sign ambiguities of dipolar couplings in fiel...

Dislocation dynamics simulations of the interaction between prismatic dipolar loops and a glide screw dislocation are presented. As a result of stress gradients generated by the glide dislocation, dipolar loops execute drift motion along their glide cylinders. Simulations of the combined motion of two dipolar loops in the stress field of a glide dislocation clearly show that inter-loop forces a...

A 13C-detected N-H dipolar coupling technique is introduced for uniaxially mobile membrane proteins for orientation determination using unoriented samples. For proteins undergoing rigid-body uniaxial rotation in the lipid bilayer, the intrinsic equality between the dipolar coupling constants measured in unoriented samples and the anisotropic coupling measured in static oriented samples has been...

Let-7 microRNA (miRNA) regulates heterochronic genes in developmental timing of the nematode Caenorhabditis elegans. Binding of miRNA to messenger RNA (mRNA) and structural features of the complex are crucial for gene silencing. We herein present the NMR solution structure of a model mimicking the interaction of let-7 miRNA with its complementary site (LCS 2) in the 3' untranslated region (3'-U...

Residual dipolar couplings and their corresponding alignment tensors are useful for structural analysis of macromolecules. The error in an alignment tensor, derived from residual dipolar couplings on the basis of a known structure, is determined not only by the accuracy of the measured couplings but also by the uncertainty in the structure (structural noise). This dependence is evaluated quanti...

DOI: 10.1002/aelm.201500070 simulations by Dvornik et al. [ 30 ] Recently, Keatley et al. [ 31 ] used a time-resolved scanning Kerr microscopy to isolate the dynamic dipolar interaction between a pair of nominally-shaped disks. However, a detailed scrutiny of phase-resolved Kerr ellipticity data is required to determine the dynamic dipolar coupling strength versus edge-to-edge spacing/diameter ...