2016 Fiscal Year Final Research Report
Structural and physiological analyses of the pressure adaptation in the deep-sea enzyme.
Project/Area Number |
25450121
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Applied microbiology
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Research Institution | Japan Agency for Marine-Earth Science and Technology |
Principal Investigator |
KATO Chiaki 国立研究開発法人海洋研究開発機構, 海洋生物多様性研究分野, シニアスタッフ (90360750)
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Co-Investigator(Renkei-kenkyūsha) |
WATANABE Nobuhisa 名古屋大学, シンクロトロン光研究センター, 教授 (70212321)
YAMADA Yasuyuki 立教大学, 理学部, 教授 (80386507)
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Project Period (FY) |
2013-04-01 – 2017-03-31
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Keywords | 高圧力 / 深海 / 微生物 / 酵素 / 構造解析 |
Outline of Final Research Achievements |
3-Isopropylmalate dehydrogenase (IPMDH) from the extreme piezophile Shewanella benthica (SbIPMDH) is more pressure-tolerant than that from the atmospheric pressure-adapted Shewanella oneidensis (SoIPMDH). To understand the molecular mechanisms of this pressure tolerance, we analyzed mutated enzymes. The results indicate that only a single mutation at position 266, corresponding to Ala (SbIPMDH) and Ser (SoIPMDH), essentially affects activity under higher-pressure (HP) conditions. 3D-structural analyses of SoIPMDH suggests that penetration of three water molecules into the cleft around Ser266 under HP conditions could reduce the activity of the wild-type enzyme; however, no water molecule is observed in the Ala266 mutant. Water penetration into the cleft under HP conditions would appear to be less frequent than for the atmospheric-adapted SoIPMDH due to the reduced probability of forming a hydrogen bond, and as a consequence, SbIPMDH could adapt to the HP conditions of the deep sea.
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Free Research Field |
微生物学、分子生物学
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