Structures of protein complexes by multidimensional heteronuclear magnetic resonance spectroscopy.

With the advent of multidimensional heteronuclear-edited and -filtered NMR experiments, the field of three-dimensional structure determination by NMR has again increased in scope, making it possible to move the technology beyond the approximately 10 kDa limit inherent to conventional two-dimensional NMR to systems up to potentially 35 to 40 kDa. This article outlines the basic strategies for solving three-dimensional structures of larger systems, in particular, protein complexes and multimeric proteins using three- and four-dimensional NMR spectroscopy, summarizes the key experiments, and illustrates the power of these methods using several examples of protein-DNA, protein-peptide complexes, and oligomeric proteins from the authors' laboratories.