title: Gibberellin-induced DELLA recognition by the gibberellin receptor GID1.
abstract: Gibberellins control a range of growth and developmental processes in higher plants and have been widely used in the agricultural industry. By binding to a nuclear receptor, GIBBERELLIN INSENSITIVE DWARF1 (GID1), gibberellins regulate gene expression by promoting degradation of the transcriptional regulator DELLA proteins, including GIBBERELLIN INSENSITIVE (GAI). The precise manner in which GID1 discriminates and becomes activated by bioactive gibberellins for specific binding to DELLA proteins remains unclear. Here we present the crystal structure of a ternary complex of Arabidopsis thaliana GID1A, a bioactive gibberellin and the amino-terminal DELLA domain of GAI. In this complex, GID1A occludes gibberellin in a deep binding pocket covered by its N-terminal helical switch region, which in turn interacts with the DELLA domain containing DELLA, VHYNP and LExLE motifs. Our results establish a structural model of a plant hormone receptor that is distinct from the mechanism of the hormone perception and effector recognition of the known auxin receptors.
authors.affiliation: Structural Biology Laboratory, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
authors.forename: Kohji
authors.initials: K
authors.lastname: Murase
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Hirano
authors.forename: Tai-ping
authors.initials: TP
authors.lastname: Sun
authors.forename: Toshio
authors.initials: T
authors.lastname: Hakoshima
mesh_terms: D020816:Amino Acid Motifs; D017360:Arabidopsis / Q000737:chemistry* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D005875:Gibberellins / Q000378:metabolism / Q000494:pharmacology*; D008954:Models, Biological; D008958:Models, Molecular; D010937:Plant Growth Regulators / Q000378:metabolism / Q000494:pharmacology*; D011485:Protein Binding; D017434:Protein Structure, Tertiary / Q000187:drug effects; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D029681:Arabidopsis Proteins; C109555:GAI protein, Arabidopsis; C512225:GID1a protein, Arabidopsis; D005875:Gibberellins; D010937:Plant Growth Regulators; D011956:Receptors, Cell Surface