Disordered proteinaceous machines

Functions of IDPs/IDPRs may arise from a specific disordered form, from interconversion between disordered forms, and from transitions between disordered and ordered states. The choice between these states is determined by the specific protein environment. Many IDPs possess an exceptional ability to fold in a template-dependent manner, where a single IDPR can bind to multiple partners gaining very different structures in the bound state. Composition-based classification takes into account a simple fact that the polypeptide chains involved in the complex formation can be identical or nonidentical, thereby giving raise to homo- and hetero-oligomers. Geometrically, units of the homo-oligomers can be organized isologously or heterologously, where isologous association involves the same surface on both monomers of the homo-oligomer, and an heterologous association relies on different interfaces.