Anomeric specificity of D-xylose isomerase.
Crystal structures of complexes of D-xylose isomerase with deoxysugars have been determined. Deoxynojirimycin is a structural analogue of alpha-pyranose and mimics the binding of these aldose substrates. The structure of this complex supports the hypothesis that an imidazole group catalyzes ring ope...
| Những tác giả chính: | , , , , , , , |
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| Định dạng: | Journal article |
| Ngôn ngữ: | English |
| Được phát hành: |
1992
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| _version_ | 1826290559370657792 |
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| author | Collyer, C Goldberg, J Viehmann, H Blow, D Ramsden, N Fleet, G Montgomery, F Grice, P |
| author_facet | Collyer, C Goldberg, J Viehmann, H Blow, D Ramsden, N Fleet, G Montgomery, F Grice, P |
| author_sort | Collyer, C |
| collection | OXFORD |
| description | Crystal structures of complexes of D-xylose isomerase with deoxysugars have been determined. Deoxynojirimycin is a structural analogue of alpha-pyranose and mimics the binding of these aldose substrates. The structure of this complex supports the hypothesis that an imidazole group catalyzes ring opening of the pyranose. The steric restrictions in the active site of the enzyme prevent a beta-pyranose from binding in the same way. For the reverse reaction with ketoses, the anomeric specificity is less certain. Dideoxyimino-D-glucitol is a structural analogue of the ketose alpha-D-furanose. The binding of the inhibitor dideoxyimino-D-glucitol to the crystals of the enzyme does not mimic the binding of the reactive alpha-D-fructofuranose. Superposition of the nonphysiological substrate alpha-D-fructofuranose onto the atomic positions of dideoxyimino-D-glucitol is not possible due to the steric restrictions of the active site. However, by utilizing the approximate 2-fold symmetry of the sugar, a stereochemically sensible model is produced which is consistent with other data. In addition to reaction with alpha-D-furanose, the enzyme probably reacts with open ring keto sugars which are present at significant concentrations. Other sugars which resemble furanoses either do not inhibit significantly or are not observed in the crystals bound in a single conformation. |
| first_indexed | 2024-03-07T02:46:02Z |
| format | Journal article |
| id | oxford-uuid:ac1c0175-df48-461b-b8e0-0fc65aacf6f1 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T02:46:02Z |
| publishDate | 1992 |
| record_format | dspace |
| spelling | oxford-uuid:ac1c0175-df48-461b-b8e0-0fc65aacf6f12022-03-27T03:26:19ZAnomeric specificity of D-xylose isomerase.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:ac1c0175-df48-461b-b8e0-0fc65aacf6f1EnglishSymplectic Elements at Oxford1992Collyer, CGoldberg, JViehmann, HBlow, DRamsden, NFleet, GMontgomery, FGrice, PCrystal structures of complexes of D-xylose isomerase with deoxysugars have been determined. Deoxynojirimycin is a structural analogue of alpha-pyranose and mimics the binding of these aldose substrates. The structure of this complex supports the hypothesis that an imidazole group catalyzes ring opening of the pyranose. The steric restrictions in the active site of the enzyme prevent a beta-pyranose from binding in the same way. For the reverse reaction with ketoses, the anomeric specificity is less certain. Dideoxyimino-D-glucitol is a structural analogue of the ketose alpha-D-furanose. The binding of the inhibitor dideoxyimino-D-glucitol to the crystals of the enzyme does not mimic the binding of the reactive alpha-D-fructofuranose. Superposition of the nonphysiological substrate alpha-D-fructofuranose onto the atomic positions of dideoxyimino-D-glucitol is not possible due to the steric restrictions of the active site. However, by utilizing the approximate 2-fold symmetry of the sugar, a stereochemically sensible model is produced which is consistent with other data. In addition to reaction with alpha-D-furanose, the enzyme probably reacts with open ring keto sugars which are present at significant concentrations. Other sugars which resemble furanoses either do not inhibit significantly or are not observed in the crystals bound in a single conformation. |
| spellingShingle | Collyer, C Goldberg, J Viehmann, H Blow, D Ramsden, N Fleet, G Montgomery, F Grice, P Anomeric specificity of D-xylose isomerase. |
| title | Anomeric specificity of D-xylose isomerase. |
| title_full | Anomeric specificity of D-xylose isomerase. |
| title_fullStr | Anomeric specificity of D-xylose isomerase. |
| title_full_unstemmed | Anomeric specificity of D-xylose isomerase. |
| title_short | Anomeric specificity of D-xylose isomerase. |
| title_sort | anomeric specificity of d xylose isomerase |
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