Nucleic acid–protein interfaces studied by MAS solid-state NMR spectroscopy

•Provides a comprehensive overview of ssNMR methods for studying nucleic acid–protein complexes.•Focusses on the characterization of intermolecular interfaces.•Demonstrates that ssNMR is mature to tackle structural studies of nucleic acid–protein complexes at atomic resolution. Solid-state NMR (ssNMR) has become a well-established technique to study large and insoluble protein assemblies. However, its application to nucleic acid–protein complexes has remained scarce, mainly due to the challenges presented by overlapping nucleic acid signals. In the past decade, several efforts have led to the first structure determination of an RNA molecule by ssNMR. With the establishment of these tools, it has become possible to address the problem of structure determination of nucleic acid–protein complexes by ssNMR. Here we review first and more recent ssNMR methodologies that study nucleic acid–protein interfaces by means of chemical shift and peak intensity perturbations, direct distance measurements and paramagnetic effects. At the end, we review the first structure of an RNA–protein complex that has been determined from ssNMR-derived intermolecular restraints.