FIGURE 3:

Mapping Su(H)-binding sites in Hairless. (A) Scheme of the HFL protein containing the Su(H)-binding domain (SBD; pink), the Groucho binding domain (GBD; blue) and a binding site for the C-terminal binding protein (CBD; yellow). Bottom, the primary sequence of the SBD is shown; the NT and CT boxes, defined by their conservation in insects, are framed in red. Amino acids that are identical in all known/predicted Hairless proteins are shown in blue and red, with the red residues (L235 and F243) indicating the mutation sites tested for Su(H) binding. (B) Yeast two-hybrid assay on the binding activity of wild-type and mutant NTCT constructs (amino acids 171–357) with full-length Su(H); empty vector served as a negative control. Note that the lack of binding for the ΔNT deletion construct is comparable to the single-site mutant L235D, whereas the F243A mutant binds Su(H) similar to wild-type NTCT.