NMR techniques for very large proteins and rnas in solution.

Three-dimensional structure determination of small proteins and oligonucleotides by solution NMR is established. With the development of novel NMR and labeling techniques, structure determination is now feasible for proteins with a molecular mass of up to approximately 100 kDa and RNAs of up to 35 kDa. Beyond these molecular masses special techniques and approaches are required for applying NMR as a multiprobe method for structural investigations of proteins and RNAs. It is the aim of this review to summarize the NMR techniques and approaches available to advance the molecular mass limit of NMR both for proteins (up to 1 MDa) and RNAs (up to 100 kDa). Physical pictures of the novel techniques, their experimental applications, as well as labeling and assignment strategies are discussed and accompanied by future perspectives.