The Structure of an FF Domain from Human HYPA/FBP11

The FF domain is a 60 amino acid residue phosphopeptide-binding module found in a variety of eukaryotic proteins including the transcription elongation factor CA150, the splicing factor Prp40 and p190RHOGAP. We have determined the structure of an FF domain from HYPA/FBP11. The domain is composed of three α helices arranged in an orthogonal bundle with a 310 helix in the loop between the second and third α helices. The structure differs from those of other phosphopeptide-binding domains and represents a novel phosphopeptide-binding fold.