title: Crystal structure of auxin-binding protein 1 in complex with auxin.
abstract: The structure of auxin-binding protein 1 (ABP1) from maize has been determined at 1.9 A resolution, revealing its auxin-binding site. The structure confirms that ABP1 belongs to the ancient and functionally diverse germin/seed storage 7S protein superfamily. The binding pocket of ABP1 is predominantly hydrophobic with a metal ion deep inside the pocket coordinated by three histidines and a glutamate. Auxin binds within this pocket, with its carboxylate binding the zinc and its aromatic ring binding hydrophobic residues including Trp151. There is a single disulfide between Cys2 and Cys155. No conformational rearrangement of ABP1 was observed when auxin bound to the protein in the crystal, but examination of the structure reveals a possible mechanism of signal transduction.
authors.affiliation: Biological Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, UK.
authors.forename: Eui-Jeon
authors.initials: EJ
authors.lastname: Woo
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Marshall
authors.forename: James
authors.initials: J
authors.lastname: Bauly
authors.forename: Jin-Gui
authors.initials: JG
authors.lastname: Chen
authors.forename: Michael
authors.initials: M
authors.lastname: Venis
authors.forename: Richard M
authors.initials: RM
authors.lastname: Napier
authors.forename: Richard W
authors.initials: RW
authors.lastname: Pickersgill
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D018360:Crystallography, X-Ray; D007210:Indoleacetic Acids / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D007210:Indoleacetic Acids; D010940:Plant Proteins; D011956:Receptors, Cell Surface; C083846:auxin-binding protein 1