title: Apo and InsP₃-bound crystal structures of the ligand-binding domain of an InsP₃ receptor.
abstract: We report the crystal structures of the ligand-binding domain (LBD) of a rat inositol 1,4,5-trisphosphate receptor (InsP(3)R) in its apo and InsP(3)-bound conformations. Comparison of these two conformations reveals that LBD's first β-trefoil fold (β-TF1) and armadillo repeat fold (ARF) move together as a unit relative to its second β-trefoil fold (β-TF2). Whereas apo LBD may spontaneously transition between gating conformations, InsP(3) binding shifts this equilibrium toward the active state.
authors: Department of Physiology, Howard Hughes Medical Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors: Chun-Chi
authors: CC
authors: Lin
authors: Kyuwon
authors: K
authors: Baek
authors: Zhe
authors: Z
authors: Lu
mesh_terms: D000818:Animals; D001665:Binding Sites; D018360:Crystallography, X-Ray; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000737:chemistry / Q000378:metabolism*; D008024:Ligands; D008958:Models, Molecular; D011487:Protein Conformation; D051381:Rats
chemical_list: D053496:Inositol 1,4,5-Trisphosphate Receptors; D008024:Ligands