3WMS
The crystal structure of Y195I mutant alpha-cyclodextrin glycosyltransferase from Paenibacillus macerans
Summary for 3WMS
| Entry DOI | 10.2210/pdb3wms/pdb |
| Descriptor | Alpha-cyclodextrin glucanotransferase, CALCIUM ION (3 entities in total) |
| Functional Keywords | tim barrel, igg-like beta-barrel, cyclodextrin glycosyltransferase, transferase |
| Biological source | Paenibacillus macerans |
| Total number of polymer chains | 1 |
| Total formula weight | 78382.51 |
| Authors | Xie, T.,Hou, Y.J.,Li, D.F.,Yue, Y.,Qian, S.J.,Chao, Y.P. (deposition date: 2013-11-24, release date: 2014-11-12, Last modification date: 2023-11-08) |
| Primary citation | Xie, T.,Hou, Y.J.,Li, D.F.,Yue, Y.,Qian, S.J.,Chao, Y.P. Structural basis of a mutant Y195I alpha-cyclodextrin glycosyltransferase with switched product specificity from alpha-cyclodextrin to beta-/ gamma-cyclodextrin J.Biotechnol., 182-183:92-96, 2014 Cited by PubMed Abstract: Cyclodextrin glycosyltransferase (EC 2.4.1.19) (CGTase) is an extracellular bacterial enzyme which has the unique capability of forming cyclodextrins from starch. Our previous investigation revealed that a mutant Y195I α-CGTase drastically altered the cyclodextrin specificity by switching toward the synthesis of both β- and γ-CDs (Xie et al., 2013a,b). In this study, we determined one X-ray structure of the mutant Y195I α-CGTase at 2.3Å. The overall structure was similar to that of the typical β-CGTase from Bacillus circulans 251, with minor difference in flexible domains since they showed about 70% homogeneity of amino acid sequences. The central site with isoleucine tended to be more flexible than tyrosine thus made the sugar chain, during the cyclization process, form a larger cyclodextrin like β- and γ-CDs surrounding the central site instead of α-CD. Superposition of the structure of Y195I α-CGTase with those of β-CGTase and γ-CGTase showed that residues Lys232, Lys89 and Arg177 at subsites +2, -3 and -7 could form smaller substrate binding cavity. In summary, the crystal structure revealed that moderate increase of mobility of the central site resulted in the switched product specificity from α-CD to β- and γ-CDs of the mutant Y195I α-CGTase. The space differences alongside the active domain may be another factor that impacts the product specificity of the CGTase. PubMed: 24637377DOI: 10.1016/j.jbiotec.2014.03.014 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.3 Å) |
Structure validation
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