title: Overexpression, purification, crystallization and preliminary crystallographic studies of a hyperthermophilic adenylosuccinate synthetase from Pyrococcus horikoshii OT3.
abstract: Adenylosuccinate synthetase (AdSS) is a ubiquitous enzyme that catalyzes the first committed step in the conversion of inosine monophosphate (IMP) to adenosine monophosphate (AMP) in the purine-biosynthetic pathway. Although AdSS from the vast majority of organisms is 430-457 amino acids in length, AdSS sequences isolated from thermophilic archaea are 90-120 amino acids shorter. In this study, crystallographic studies of a short AdSS sequence from Pyrococcus horikoshii OT3 (PhAdSS) were performed in order to reveal the unusual structure of AdSS from thermophilic archaea. Crystals of PhAdSS were obtained by the microbatch-under-oil method and X-ray diffraction data were collected to 2.50 Å resolution. The crystal belonged to the trigonal space group P3(2)12, with unit-cell parameters a = b = 57.2, c = 107.9 Å. There was one molecule per asymmetric unit, giving a Matthews coefficient of 2.17 Å(3) Da(-1) and an approximate solvent content of 43%. In contrast, the results of native polyacrylamide gel electrophoresis and analytical ultracentrifugation showed that the recombinant PhAdSS formed a dimer in solution.
authors.affiliation: Institute of Medicinal Plants, Chinese Academy of Medical Sciences and Peking Union Medical College, Haidian District, Beijing, People's Republic of China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Wang
authors.forename: Ryogo
authors.initials: R
authors.lastname: Akasaka
authors.forename: Chie
authors.initials: C
authors.lastname: Takemoto
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morita
authors.forename: Machiko
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Takaho
authors.initials: T
authors.lastname: Terada
authors.forename: Mikako
authors.initials: M
authors.lastname: Shirozu
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Shilin
authors.initials: S
authors.lastname: Chen
authors.forename: Shuyi
authors.initials: S
authors.lastname: Si
authors.forename: Yong
authors.initials: Y
authors.lastname: Xie
mesh_terms: D000265:Adenylosuccinate Synthase / Q000737:chemistry* / Q000302:isolation & purification; D000595:Amino Acid Sequence; D003460:Crystallization; D018360:Crystallography, X-Ray; D008969:Molecular Sequence Data; D043902:Pyrococcus horikoshii / Q000201:enzymology*; D016415:Sequence Alignment
chemical_list: D000265:Adenylosuccinate Synthase