title: Structure of FBP11 WW1-PL ligand complex reveals the mechanism of proline-rich ligand recognition by group II/III WW domains.
abstract: FBP11/HYPA is a mammalian homologue of yeast splicing factor Prp40. The first WW domain of FBP11/HYPA (FBP11 WW1) is essential for preventing severe neurological diseases such as Huntington disease and Rett syndrome and strongly resembles the WW domain of FCA, the essential regulator for flowering time control. We have solved the structure of FBP11 WW1 and a Pro-Pro-Leu-Pro ligand complex, and demonstrated the binding mechanism with mutational analysis using surface plasmon resonance. The overall structure of FBP11 WW1 in the complex form is quite similar to the structures of WW domains from Group I and IV in complexes. In addition, conformation of FBP11 WW1 does not change much upon ligand binding. The binding orientation of the ligand against FBP11 WW1 is the same as that of the Group IV WW domain-ligand complex, but opposite to that of the Group I complex. The ligand interacts with two grooves formed by surface aromatic residues. The Pro and Leu residues in the ligand interact with the grooves and the Loop I region of FBP11 WW1, respectively, which are necessary interactions for binding the ligand. Interestingly, the two aromatic grooves recognize the Pro residues in entirely different manners, which allows FBP11 WW1 to recognize shorter sequences than the SH3 domain. Combined with homology models of other WW domains, the present report shows the detailed mechanism of ligand binding by Group II/III WW domains, and provides information useful in designing drugs to treat neurodegenerative diseases.
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kato
authors.forename: Takuya
authors.initials: T
authors.lastname: Miyakawa
authors.forename: Jun-Ichi
authors.initials: J
authors.lastname: Kurita
authors.forename: Masaru
authors.initials: M
authors.lastname: Tanokura
mesh_terms: D020816:Amino Acid Motifs / Q000502:physiology; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D006801:Humans; D006816:Huntington Disease / Q000378:metabolism / Q000473:pathology; D007930:Leucine / Q000737:chemistry* / Q000378:metabolism; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D011392:Proline / Q000737:chemistry* / Q000378:metabolism; D055232:Proline-Rich Protein Domains; D017434:Protein Structure, Tertiary; D015518:Rett Syndrome / Q000378:metabolism / Q000473:pathology; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000737:chemistry / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D014364:Tryptophan / Q000737:chemistry* / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D008024:Ligands; C491404:PRPF40A protein, human; D010455:Peptides; C120813:Prp40 protein, S cerevisiae; D017412:Ribonucleoprotein, U1 Small Nuclear; D029701:Saccharomyces cerevisiae Proteins; D014364:Tryptophan; D011392:Proline; D007930:Leucine