Characterizing structural disorder through NMR: new methods and applications

Intrinsically Disordered Proteins (IDPs) are flexible proteins that challenge structural biology due to the fact that they cannot be studied with the standard methods developed to characterize well-folded proteins. In the last decades, the discovery of their widespread presence and involvement in many biological functions, despite their deviation from the structure-function paradigm, has pushed the scientific community towards a growing acceptance of the importance of IDPs and to the development of new tools for studying their structure, dynamics and functions. In this context, Nuclear Magnetic Resonance (NMR) spectroscopy plays the leading role of most suitable technique to characterize IDPs. In this doctoral thesis, my contribution to the advancement of NMR spectroscopy, achieved by developing new experiments to study IDPs, is described. The new methods enable the characterization of structural disorder and allow to address topics of general interest such as the study of protein linkers and low-complexity regions, two areas of high biological relevance for which only very limited atomic resolution information is available so far. The methodological progress in NMR and the findings on the studied IDPs reported here give a contribution to the discovery of new roles for structural disorder and prompt towards an unified understanding of structure-dynamicsdisorder/function relationships.