title: Crystallization and preliminary X-ray crystallographic analysis of L-arabinose isomerase from thermophilic Geobacillus kaustophilus.
abstract: L-arabinose isomerase (AI), which catalyzes the isomerization of L-arabinose to L-ribulose, can also convert D-galactose to D-tagatose, a natural sugar replacer, which is of commercial interest in the food and healthcare industries. Intriguingly, mesophilic and thermophilic AIs showed different substrate preferences and metal requirements in catalysis and different thermostabilities. However, the catalytic mechanism of thermophilic AIs still remains unclear. Therefore, thermophilic Geobacillus kaustophilus AI (GKAI) was overexpressed, purified and crystallized, and a preliminary X-ray diffraction data set was obtained. Diffraction data were collected from a GKAI crystal to 2.70 Å resolution. The crystal belonged to the monoclinic space group C2, with unit-cell parameters a = 224.12, b = 152.95, c = 91.28 Å, β = 103.61°. The asymmetric unit contained six molecules, with a calculated Matthews coefficient of 2.25 Å(3) Da(-1) and a solvent content of 45.39%. The three-dimensional structure determination of GKAI is currently in progress by molecular replacement and model building.
authors.affiliation: Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 375 Seo-suk dong, Gwangju 501-759, Republic of Korea.
authors.forename: Thinh-Phat
authors.initials: TP
authors.lastname: Cao
authors.affiliation: Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 375 Seo-suk dong, Gwangju 501-759, Republic of Korea.
authors.forename: Jin Myung
authors.initials: JM
authors.lastname: Choi
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Sang-Jae
authors.initials: SJ
authors.lastname: Lee
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Yong-Jik
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: Department of Pharmacology, College of Medicine, Inha University, Incheon 400-712, Republic of Korea.
authors.forename: Sung-Keun
authors.initials: SK
authors.lastname: Lee
authors.affiliation: Bio-Imaging and Cell Dynamics Research Center, School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, Republic of Korea.
authors.forename: Youngsoo
authors.initials: Y
authors.lastname: Jun
authors.affiliation: School of Applied Biosciences, Kyungpook National University, Daegu 702-701, Republic of Korea.
authors.forename: Dong-Woo
authors.initials: DW
authors.lastname: Lee
authors.affiliation: Department of Cellular and Molecular Medicine, Chosun University School of Medicine, 375 Seo-suk dong, Gwangju 501-759, Republic of Korea.
authors.forename: Sung Haeng
authors.initials: SH
authors.lastname: Lee
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D004591:Electrophoresis, Polyacrylamide Gel; D056506:Geobacillus / Q000201:enzymology*; D013696:Temperature
chemical_list: D019747:Aldose-Ketose Isomerases; C019715:L-arabinose isomerase
keywords: Geobacillus kaustophilus; l-arabinose isomerase