2010 Fiscal Year Final Research Report
A novel reduction-stress elimination system by the Escherichia coli DsbA and its application to L-cysteine production
| Project/Area Number |
21780073
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Applied microbiology
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| Research Institution | Nara Institute of Science and Technology |
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Principal Investigator |
OHTSU Iwao Nara Institute of Science and Technology, バイオサイエンス研究科, 助教 (60395655)
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| Co-Investigator(Renkei-kenkyūsha) |
MORI Hirotada 奈良先端科学技術大学院大学, バイオサイエンス研究科, 教授 (90182203)
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| Project Period (FY) |
2009 – 2010
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| Keywords | 発酵生産 |
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| Research Abstract |
DsbA oxidizes peptidyl L-cysteine residue into disulfide bridge in the periplasm, and the reduced form of DsbA is re-oxidized by inner membrane protein DsbB. Electron, which is received from ubiquinone, is given to DsbA. Finally, oxygen is an electron acceptor through the terminal oxidase of the respiratory chain (DsbA-DsbB-UQ complex). We find that DsbA, which is normally the oxidized form, is shifted in the reduced form of DsbA in the addition of excess Cys. Furthermore, OstA protein, which is one of the DsbA substrates and is an essential protein for Escherichia coli growth, is also accumulated as reduced form into the periplasm. We suggested that the DsbA-DsbB-ubiquinone oxidation system might eliminate reductive stress by oxidizing exogenous reductants and also play an important role in redox homeostasis in the cytoplasm. A similar mechanism to DsbA-DsbB-ubiquinone oxidation system of E. coli exists widely also in endoplasmic reticulum of yeast, the plant, and the animal, etc. and mitochondria. This is corresponding to the toxicity of Cys that exceeds the living thing kind.
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Research Products
(12 results)
