INTRINSICALLY DISORDERED REGIONS AND ADAPTATION

Intrinsically disordered proteins (IDPs), i.e. proteins lacking a unique 3D structure and yet capable of exerting important biological functions, challenge the so-called “structure-function relationship” dogma. RNA viruses have a large proportion of intrinsically disordered regions (IDRs) in their proteins. It has been proposed that IDRs, because of their weak topological requirements, possess a mutational robustness higher than that of ordered regions (ODRs), contributing to a rapid adaptation to environmental stresses, without excessive loss of fitness. Consequently, the high evolutionary potential of RNA viruses, and the high content in ID of their proteins, set the basis for assessing the contribution of ID to the mutational robustness in a context of host adaptation.