Influencing the binding configuration of sucrose in the active sites of chicory fructan 1-exohydrolase and sugar beet fructan 6-exohydrolase
The hydrolytic plant enzymes of family 32 of glycoside hydrolases (GH32), including acid cell wall type invertases (EC 3.2.1.26), fructan 1-exohydrolases (1-FEH; EC 3.2.1.153) and fructan 6-exohydrolases (6-FEH; EC 3.2.1.154), are very similar at the molecular and structural levels, but are clearly...
| Veröffentlicht in: | The New phytologist. - 1979. - 178(2008), 3 vom: 15., Seite 572-80 |
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| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2008
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Plant Proteins Sucrose 57-50-1 Glycoside Hydrolases EC 3.2.1.- |
| Zusammenfassung: | The hydrolytic plant enzymes of family 32 of glycoside hydrolases (GH32), including acid cell wall type invertases (EC 3.2.1.26), fructan 1-exohydrolases (1-FEH; EC 3.2.1.153) and fructan 6-exohydrolases (6-FEH; EC 3.2.1.154), are very similar at the molecular and structural levels, but are clearly functionally different. The work presented here aims at understanding the evolution of enzyme specificity and functional diversity in this family by means of site-directed mutagenesis. It is demonstrated for the first time that invertase activity can be introduced in an S101L mutant of chicory (Cichorium intybus) 1-FEH IIa by influencing the orientation of Trp 82. At high sucrose and enzyme concentrations, a shift is proposed from a stable inhibitor configuration to an unstable substrate configuration. In the same way, invertase activity was introduced in Beta vulgaris 6-FEH by introducing an acidic amino acid in the vicinity of the acid-base catalyst (F233D mutant), creating a beta-fructofuranosidase type of enzyme with dual activity against sucrose and levan. As single amino acid substitutions can influence the donor substrate specificity of FEHs, it is predicted that plant invertases and FEHs may have diversified by introduction of a very limited number of mutations in the common ancestor |
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| Beschreibung: | Date Completed 27.10.2008 Date Revised 09.01.2024 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/j.1469-8137.2008.02386.x |