Academic Journal
Structural analysis, enzymatic characterization, and catalytic mechanisms of β‐galactosidase from Bacillus circulans sp. alkalophilus
| العنوان: | Structural analysis, enzymatic characterization, and catalytic mechanisms of β‐galactosidase from Bacillus circulans sp. alkalophilus |
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| المؤلفون: | Maksimainen, Mirko, Paavilainen, Sari, Hakulinen, Nina, Rouvinen, Juha |
| المصدر: | The FEBS Journal ; volume 279, issue 10, page 1788-1798 ; ISSN 1742-464X 1742-4658 |
| بيانات النشر: | Wiley |
| سنة النشر: | 2012 |
| المجموعة: | Wiley Online Library (Open Access Articles via Crossref) |
| الوصف: | Crystal structures of native and α‐ d ‐galactose‐bound Bacillus circulans sp. alkalophilus β‐galactosidase (Bca‐β‐gal) were determined at 2.40 and 2.25 Å resolutions, respectively. Bca‐β‐gal is a member of family 42 of glycoside hydrolases, and forms a 460 kDa hexameric structure in crystal. The protein consists of three domains, of which the catalytic domain has an (α/β) 8 barrel structure with a cluster of sulfur‐rich residues inside the β‐barrel. The shape of the active site is clearly more open compared to the only homologous structure available in the Protein Data Bank. This is due to the number of large differences in the loops that connect the C‐terminal ends of the β‐strands to the N‐terminal ends of the α‐helices within the (α/β) 8 barrel. The complex structure shows that galactose binds to the active site as an α‐anomer and induces clear conformational changes in the active site. The implications of α‐ d ‐galactose binding with respect to the catalytic mechanism are discussed. In addition, we suggest that β‐galactosidases mainly utilize a reverse hydrolysis mechanism for synthesis of galacto‐oligosaccharides. Database The coordinates for free and α‐ d ‐galactose‐bound Bca‐β‐gal structures have been deposited in the Research Collaboratory for Structural Bioinformatics (RCSB) Protein Data Bank under accession codes 3TTS and 3TTY , respectively. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| DOI: | 10.1111/j.1742-4658.2012.08555.x |
| الاتاحة: | http://dx.doi.org/10.1111/j.1742-4658.2012.08555.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1742-4658.2012.08555.x https://febs.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1742-4658.2012.08555.x |
| Rights: | http://onlinelibrary.wiley.com/termsAndConditions#vor |
| رقم الانضمام: | edsbas.513A9803 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1111/j.1742-4658.2012.08555.x |
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