Figure 14.

Repeat expansion creates IDRs. IDRs are abundant in repeating sequence elements, which suggests that repeat expansion is an important mechanism by which genetic material encoding for structural disorder is generated. The expanding repeats may fall into three classes (types) in terms of their functional diversification following expansion. Individual repeats may remain functionally equivalent (type I), or diversify (type II), or collectively acquire a completely new function (type III). Dark-tone red indicates structural disorder of the repeat, which may undergo full (dark-tone blue) or partial (green) induced folding upon binding to a partner. Adapted with permission from ref (61). Copyright 2003 John Wiley & Sons, Inc.