The SUFU IDR has distinct structural properties. (a) Thermal stability assays of MBP-SUFU constructs performed in triplicate, either alone (blue) or with GLI1p (red) or GLI1p-SH (green). All constructs bind to GLI1p; however, MBP-SUFU-FL has different physical properties upon initial GLI1p binding, as shown by the marked increase in fluorescence. (b) Microscale thermophoresis experiments with FAM-GLI1p and titrated MBP-SUFU constructs, showing an average of three separate experiments. All proteins have similar affinity, but the thermophoretic properties of FAM-GLI1p are modified differently between the MBP-SUFU-FL construct and the MBP-SUFU-Δ and MBP-SUFU-SH constructs, reflecting a difference in shape.