The structural analysis of protein-protein interactions by NMR spectroscopy.

A comprehensive understanding of protein-protein interactions is an important next step in our quest to understand how the information contained in a genome is put into action. Although a number of experimental techniques can report on the existence of a protein- protein interaction, very few can provide detailed structural information. NMR spectroscopy is one of these, and in recent years several complementary NMR approaches, including residual dipolar couplings and the use of paramagnetic effects, have been developed that can provide insight into the structure of protein-protein complexes. In this article, we review these approaches and comment on their strengths and weaknesses.