title: Crystallization and preliminary X-ray diffraction analysis of the periplasmic domain of the Escherichia coli aspartate receptor Tar and its complex with aspartate.
abstract: The cell-surface receptor Tar mediates bacterial chemotaxis toward an attractant, aspartate (Asp), and away from a repellent, Ni(2+). To understand the molecular mechanisms underlying the induction of Tar activity by its ligands, the Escherichia coli Tar periplasmic domain with and without bound aspartate (Asp-Tar and apo-Tar, respectively) were each crystallized in two different forms. Using ammonium sulfate as a precipitant, crystals of apo-Tar1 and Asp-Tar1 were grown and diffracted to resolutions of 2.10 and 2.40 Å, respectively. Alternatively, using sodium chloride as a precipitant, crystals of apo-Tar2 and Asp-Tar2 were grown and diffracted to resolutions of 1.95 and 1.58 Å, respectively. Crystals of apo-Tar1 and Asp-Tar1 adopted space group P41212, while those of apo-Tar2 and Asp-Tar2 adopted space groups P212121 and C2, respectively.
authors.affiliation: Information Processing Biology Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami, Okinawa 904-0495, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Mise
authors.affiliation: Trans-Membrane Trafficking Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami, Okinawa 904-0495, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Matsunami
authors.affiliation: Trans-Membrane Trafficking Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami, Okinawa 904-0495, Japan.
authors.forename: Fadel A
authors.initials: FA
authors.lastname: Samatey
authors.affiliation: Information Processing Biology Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna-son, Kunigami, Okinawa 904-0495, Japan.
authors.forename: Ichiro N
authors.initials: IN
authors.lastname: Maruyama
mesh_terms: D001224:Aspartic Acid / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D001483:Base Sequence; D003460:Crystallization; D018360:Crystallography, X-Ray; D017931:DNA Primers; D004926:Escherichia coli / Q000737:chemistry*; D019897:Periplasm / Q000737:chemistry*; D010957:Plasmids; D016133:Polymerase Chain Reaction; D017459:Receptors, Amino Acid / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D017459:Receptors, Amino Acid; C031959:aspartic acid receptor; D001224:Aspartic Acid
keywords: Escherichia coli; attractant; bacterial chemotaxis; cell-surface receptor; transmembrane signalling