1. Crystallization and preliminary X-ray crystallographic analysis of α-glucosidase HaG from Halomonas sp. strain H11.
- Author
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Shen, Xing, Saburi, Wataru, Gai, Zuo-Qi, Komoda, Keisuke, Yu, Jian, Ojima-Kato, Teruyo, Kido, Yusuke, Matsui, Hirokazu, Mori, Haruhide, and Yao, Min
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GLUCOSIDASES ,MOLECULAR weights ,AMINO acid sequence ,HALOMONAS (Bacteria) ,SUCROSE - Abstract
The α-glucosidase HaG from the halophilic bacterium Halomonas sp. strain H11 catalyzes the hydrolysis of the glucosidic linkage at the nonreducing end of α-glucosides, such as maltose and sucrose, to release α-glucose. Based on its amino-acid sequence, this enzyme is classified as a member of glycoside hydrolase family 13. HaG has three unique characteristics: (i) a very narrow substrate specificity, almost exclusively hydrolyzing disaccharides; (ii) activation by monovalent cations, such as K
+ , Rb+ , Cs+ and NH4 + ; and (iii) high transfer activity of the glucose moiety to the OH group of low-molecular-weight compounds, including glycerol and 6-gingerol. Crystallographic studies have been performed in order to understand these special features. An expression vector was constructed and recombinant HaG protein was overexpressed, purified and crystallized. A data set to 2.15 Å resolution was collected and processed. The crystal belonged to space group P21 21 21 , with unit-cell parameters a = 60.2, b = 119.2, c = 177.2 Å. The structure has been determined by molecular replacement using the isomaltulose synthase PalI as the search model (PDB entry ). [ABSTRACT FROM AUTHOR]- Published
- 2014
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