Crystallization and preliminary X-ray crystallographic analysis of l-Arabinose isomerase from thermophilic Geobacillus kaustophilus

Thinh-Phat Cao, Jin Myung Choi, Sang Jae Lee, Yong Jik Lee, Sung Keun Lee, Youngsoo Jun, Dong Woo Lee, Sung Haeng Lee

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5 Citations (Scopus)


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 Å3 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.

Original languageEnglish
Pages (from-to)108-112
Number of pages5
JournalActa Crystallographica Section F: Structural Biology Communications
Issue number1
Publication statusPublished - 1 Jan 2014
Externally publishedYes


  • Geobacillus kaustophilus
  • l-Arabinose isomerase

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