MBP-SUFU and GLI peptides interact in the same way in solution as in crystals. (a) HDX analysis of MBP-SUFU-FL with GLI3p (blue). Areas that are more protected from exchange in the presence of the peptide are highlighted in pink. (b) Comparison of SAXS envelopes for MBP-SUFU-Δ in the absence (left) and presence (right) of GLI1p. Crystal structures of apo MBP-SUFU-Δ and of MBPA216H_K220H-SUFU-ΔW61D_L62S_G63F_P453A_Δ454–456_K457A co-crystallized with GLI3p superpose well on apo and holo SAXS envelopes, respectively.