title: Crystallization and preliminary X-ray crystallographic study of a putative aspartyl-tRNA synthetase from the crenarchaeon Sulfolobus tokodaii strain 7.
abstract: Genome analysis suggests that the aspartyl-tRNA synthetase of the crenarchaeon Sulfolobus tokodaii strain 7 belongs to the nondiscriminating type that is believed to catalyze aspartylation of tRNA(Asp) and tRNA(Asn). This protein has been overexpressed in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method from 100 mM sodium HEPES buffer pH 7.5 containing 100 mM NaCl and 1.6 M (NH4)2SO4 as the crystallizing reagent. Diffraction data were collected to 2.3 A resolution using synchrotron radiation. The crystal belongs to the orthorhombic space group P2(1)2(1)2, with unit-cell parameters a = 116.0, b = 139.3, c = 75.3 A. The estimated Matthews coefficient (3.10 A3 Da(-1); 60.3% solvent content) suggests the presence of two subunits in the asymmetric unit. The structure has been successfully solved by the molecular-replacement method. Full refinement of the structure may reveal it to be the original ancestor of the nondiscriminating AspRS.
authors.affiliation: College of Science and Engineering, Iwaki-Meisei University, Chuou-dai-Iino, Iwaki, Fukushima 970-8551, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Suzuki
authors.forename: Yoshiteru
authors.initials: Y
authors.lastname: Sato
authors.forename: Yohei
authors.initials: Y
authors.lastname: Maeda
authors.forename: Satoru
authors.initials: S
authors.lastname: Shimizu
authors.forename: Md Tofazzal
authors.initials: MT
authors.lastname: Hossain
authors.forename: Souichirou
authors.initials: S
authors.lastname: Ubukata
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sekiguchi
authors.forename: Akio
authors.initials: A
authors.lastname: Takénaka
mesh_terms: D019843:Archaeal Proteins / Q000737:chemistry*; D001226:Aspartate-tRNA Ligase / Q000737:chemistry*; D019615:Crenarchaeota / Q000201:enzymology; D003460:Crystallization; D018360:Crystallography, X-Ray; D016944:Sulfolobus / Q000201:enzymology*
chemical_list: D019843:Archaeal Proteins; D001226:Aspartate-tRNA Ligase