title: Crystallization and preliminary X-ray crystallographic studies of dehydroascorbate reductase (DHAR) from Oryza sativa L. japonica.
abstract: Dehydroascorbate reductase from Oryza sativa L. japonica (OsDHAR), a key enzyme in the regeneration of vitamin C, maintains reduced pools of ascorbic acid to detoxify reactive oxygen species. In previous studies, the overexpression of OsDHAR in transgenic rice increased grain yield and biomass as well as the amount of ascorbate, suggesting that ascorbate levels are directly associated with crop production in rice. Hence, it has been speculated that the increased level of antioxidants generated by OsDHAR protects rice from oxidative damage and increases the yield of rice grains. However, the crystal structure and detailed mechanisms of this important enzyme need to be further elucidated. In this study, recombinant OsDHAR protein was purified and crystallized using the sitting-drop vapour-diffusion method at pH 8.0 and 298 K. Plate-shaped crystals were obtained using 0.15 M potassium bromide, 30%(w/v) PEG MME 2000 as a precipitant, and the crystals diffracted to a resolution of 1.9 Å on beamline 5C at the Pohang Accelerator Laboratory. The X-ray diffraction data indicated that the crystal contained one OsDHAR molecule in the asymmetric unit and belonged to space group P2₁ with unit-cell parameters a=47.03, b=48.38, c=51.83 Å, β=107.41°.
authors.affiliation: Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Republic of Korea.
authors.forename: Hackwon
authors.initials: H
authors.lastname: Do
authors.affiliation: Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Il-Sup
authors.initials: IS
authors.lastname: Kim
authors.affiliation: Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Young-Saeng
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Sun-Young
authors.initials: SY
authors.lastname: Shin
authors.affiliation: Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Jin-Ju
authors.initials: JJ
authors.lastname: Kim
authors.affiliation: Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Ji-Eun
authors.initials: JE
authors.lastname: Mok
authors.affiliation: Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Seong-Im
authors.initials: SI
authors.lastname: Park
authors.affiliation: Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Republic of Korea.
authors.forename: Ah Ram
authors.initials: AR
authors.lastname: Wi
authors.affiliation: Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Republic of Korea.
authors.forename: Hyun
authors.initials: H
authors.lastname: Park
authors.affiliation: Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Republic of Korea.
authors.forename: Han-Woo
authors.initials: HW
authors.lastname: Kim
authors.affiliation: Department of Biology, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Ho-Sung
authors.initials: HS
authors.lastname: Yoon
authors.affiliation: Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, Republic of Korea.
authors.forename: Jun Hyuck
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray; D008969:Molecular Sequence Data; D012275:Oryza / Q000201:enzymology*; D010088:Oxidoreductases / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid
chemical_list: D010088:Oxidoreductases; C020666:glutathione dehydrogenase (ascorbate)
keywords: Oryza sativa L. japonica; ascorbate; dehydroascorbate reductase