Allosteric Regulation of Epoxide Opening Cascades by a Pair of Epoxide Hydrolases in Monensin Biosynthesis
| Autor: | Azusa Oikawa, Toyoyuki Ose, Kyohei Sato, Katsumi Maenaka, Hideaki Oikawa, Kimiko Kuroki, Atsushi Minami, Hiroki Oguri |
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| Rok vydání: | 2013 |
| Předmět: |
Epoxide Hydrolases
Models Molecular Bicyclic molecule Protein Conformation Stereochemistry Allosteric regulation Epoxide General Medicine Isomerase Crystallography X-Ray Biochemistry Cyclase Streptomyces chemistry.chemical_compound Allosteric Regulation chemistry Biosynthesis Mutation Molecular Medicine Monensin Protein Multimerization Epoxide hydrolase |
| Zdroj: | ACS Chemical Biology. 9:562-569 |
| ISSN: | 1554-8937 1554-8929 |
| Popis: | Multistep catalysis of epoxide hydrolase/cyclase in the epoxide opening cascade is an intriguing issue in polyether biosynthesis. A pair of structurally homologous epoxide hydrolases was found in gene clusters of ionophore polyethers. In the epoxide opening reactions with MonBI and MonBII involved in monensin biosynthesis, we found that MonBII and catalytically inactive MonBI mutant catalyzed two-step reactions of bisepoxide substrate analogue to afford bicyclic product although MonBII alone catalyzed only the first cyclization. The X-ray crystal structure of MonBI dimers suggested the importance of the KSD motif in MonBI/MonBI interaction, which was further supported by gel filtration chromatography of wild-type MonBI and mutant MonBI. The involvement of the KSD motif in heterodimer formation was confirmed by in vitro assay. Direct evidence of MonBI/MonBII interaction was obtained by native mass spectrometry. Its dissociation constant was determined as 2.21 × 10(-5) M by surface plasmon resonance. Our results suggested the involvement of an allosteric regulation mechanism by MonBI/MonBII interaction in monensin skeletal construction. |
| Databáze: | OpenAIRE |
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