Fig. 7.

Diagram of states for IDPs. We focus on sequences that fall below the parameterized line (NCPR = 2.785H − 1.151), developed by Uversky et al. (43) to separate IDPs from sequences that fold autonomously. Here, H refers to the hydropathy score. Region 1 corresponds to either weak polyampholytes or weak polyelectrolytes that form globule or tadpole-like conformations (SI Appendix, Fig. S17). Region 3 corresponds to strong polyampholytes that form distinctly nonglobular conformations that are coil-like, hairpin-like, or admixtures. A boundary region labeled 2 separates regions 1 and 3, and the conformations within this region are likely to represent a continuum of possibilities between the types of conformations adopted by sequences in regions 1 and 3. Sequences with compositions corresponding to regions 4 and 5 are strong polyelectrolytes with FCR > 0.35 and NCPR > 0.3. These sequences are expected to sample coil-like conformations that largely resemble EV limit ensembles. The legend summarizes statistics for different regions based on sequences drawn from the DisProt database. The figure includes annotation by properties of sequences that have been designated as being “coils” or “pre-molten-globules” by Uversky (3) based on measurements of hydrodynamic radii. These sequences (listed in SI Appendix, Tables S3 and S4) are expected to be expanded vis-à-vis folded proteins, and our annotation shows that, indeed, all but one of the sequences is outside the globule-forming region.