Figure 5

Example of a flexible disordered linker. The intrinsically disordered protein Sic1 binds to the CDC4 subunit of an SCF ubiquitin ligase forming a fuzzy complex (data for the structural ensemble obtained from the Protein Ensemble Database, PED). Two conformations of the same Sic1 fragment from the ensemble of this complex are displayed on panels A and B. Below, the DisCons profile on panel C corresponds to the same fragment, and shows the segment that is flexible disordered between two constrained disordered regions (1st MoRF and 2nd MoRF) that bind to Cdc4. This former segment corresponds to a flexible linker (shown in orange in panels A and B), which is found between two MoRFs (1st and 2nd on panels A and B) that bind to the same binding pocket in the fuzzy complex. The flexible conservation of the linker indicates that the sequence is of less importance than its conformational flexibility.