title: Structural basis for recognition of ubiquitinated cargo by Tom1-GAT domain.
abstract: Tom1 (Target of Myb1) is suggested to be involved in the transport of ubiquitinated proteins, through the interaction of its GAT (GGA and Tom1) domain with ubiquitin. Here, we demonstrate that the three-helix bundle of Tom1-GAT has two ubiquitin-binding sites recognizing the hydrophobic Ile44 surface of ubiquitin. The complex crystal structure demonstrates that the first site is a hydrophobic patch on helices alpha1 and alpha2. NMR and biochemical data revealed that the N-terminal half of helix alpha3 of Tom1-GAT constitutes the second, stronger binding site. The double-sided ubiquitin binding enhances the efficiency of recognition of ubiquitinated proteins by Tom1.
authors.affiliation: Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan
authors.forename: Masato
authors.initials: M
authors.lastname: Akutsu
authors.forename: Masato
authors.initials: M
authors.lastname: Kawasaki
authors.forename: Yohei
authors.initials: Y
authors.lastname: Katoh
authors.forename: Tomoo
authors.initials: T
authors.lastname: Shiba
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Kato
authors.forename: Koichi
authors.initials: K
authors.lastname: Kato
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Nakayama
authors.forename: Soichi
authors.initials: S
authors.lastname: Wakatsuki
mesh_terms: D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D004591:Electrophoresis, Polyacrylamide Gel; D050485:GABA Plasma Membrane Transport Proteins / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation; D011506:Proteins / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D020349:Surface Plasmon Resonance; D025801:Ubiquitin / Q000378:metabolism*
chemical_list: D050485:GABA Plasma Membrane Transport Proteins; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; C493413:SLC6A1 protein, human; C120296:TOM1 protein, human; D025801:Ubiquitin