Recent progress in the study of biomolecular structure and dynamics in solution from residual dipolar couplings

The recent developments in the use of dipolar couplings measured in the nuclear magnetic resonance (NMR) spectrum of weakly aligned macromolecules for the study of biomolecular structure and dynamics in the solution state are discussed. Analytical description of dipolar couplings in terms of structure and dynamics and the structural dependence of residual dipolar couplings (RDC) are also presented. Use of RDCs in structure determination of proteins and nucleic acids, including determination of the relative orientations in biomolecules are described. The RDCs are also used to characterize dynamic modes and to extract motional amplitudes of protein sidechains.