Expanding the NMR toolbox for integrated structural biology

The research is embedded in the scientific field of Integrative Structural Biology. This method uses a plethora of approaches (Cryo-EM, NMR spectroscopy, small angle neutron/x-ray scattering, and others) to address structural and functional features of biomolecular complexes. The potential of the approach to study RNA protein complexes (RNPs) became recently obvious. These complexes are in the main focus of structural biology as both biomolecules are central building blocks of molecular machines. We plan to develop protocols that will allow to make the nucleic acids component of RNPs visible via solution (and also solid) state NMR spectroscopy even in high molecular weight entities. To this end, we will establish a stable isotope labeling pattern relying on 13C-labeled methyl groups and 15N1-purines and 15N3-pyrimidines in an otherwise deuterated background. These labeling schemes mimic current state of the art protein methods and we think that the planned research project will help to better understand the function of the RNA component in RNPs.

The research was embedded in the scientific field of integrative structural biology. In the project carried out, new methods for stable isotope labeling of RNA were established. Deviating from the original project, a 19F-13C labeling pattern proved to be extremely effective for studying large RNAs using solution nuclear magnetic resonance. Furthermore, a new method was developed to provide RNA with reporter groups in a site-specific manner. This enables the application of new solution nuclear magnetic resonance methods to RNA that were previously only possible for proteins. Through the synthetic access to amino-modified RNA building blocks and their fully controllable incorporation into an oligonucleotide sequence, anchor points for the reporter functions can be set arbitrarily. The new labeling schemes mimic current state-of-the-art protein methods and now allow the structure and function of large RNAs to be better understood using solution nuclear magnetic resonance.