The existence of intrinsically disordered proteins (IDPs) that lack well-folded states yet fulfill key biological roles has challenged the classical structure–function paradigm. Their recognition led to the onset of an entire field that aims to elaborate the structural characteristics and mechanism of action of IDPs. Based on bioinformatics predictions, IDPs are abundant in different genomes and carry out mostly regulatory functions that are often related to molecular recognition. Biophysical data provide evidence that most IDPs do not behave like fully random coils, but rather exhibit a limited structural organization either at a secondary or tertiary structure level. Residual structures of IDPs, which are often distinguished in interactions with their partners, are described by related concepts of preformed elements, molecular recognition features, primary contact sites, or linear motifs. All these structural elements act as recognition motifs that facilitate formation of productive contacts with the target and result in specific binding modes. IDPs often adopt a partly or fully folded state in their bound form, yet their interactions and the nature of the interfaces are distinct from that of globular proteins. Although many details are yet to be revealed, the basic concepts of IDP action transform our view on the structural basis of protein functionality.
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Biochemistry, Genetics and Molecular Biology(all)