title: Pressure adaptation of 3-isopropylmalate dehydrogenase from an extremely piezophilic bacterium is attributed to a single amino acid substitution.
abstract: 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 conditions. Structural analyses of SoIPMDH suggests that penetration of three water molecules into the cleft around Ser266 under high-pressure conditions could reduce the activity of the wild-type enzyme; however, no water molecule is observed in the Ala266 mutant.
authors: Department of Marine Biodiversity Research, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa, 237-0061, Japan.|Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo, 171-8501, Japan.
authors: Yuki
authors: Y
authors: Hamajima
authors: Synchrotron Radiation Research Center, Nagoya University, Furo-cho, Chigusa-ku, Nagoya, Aichi, 464-8603, Japan.
authors: Takayuki
authors: T
authors: Nagae
authors: Synchrotron Radiation Research Center, Nagoya University, Furo-cho, Chigusa-ku, Nagoya, Aichi, 464-8603, Japan.|Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chigusa-ku, Nagoya, Aichi, 464-8603, Japan.
authors: Nobuhisa
authors: N
authors: Watanabe
authors: Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, 1-3-2 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8511, Japan.
authors: Eiji
authors: E
authors: Ohmae
authors: Department of Life Science, College of Science, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima-ku, Tokyo, 171-8501, Japan.
authors: Yasuyuki
authors: Y
authors: Kato-Yamada
authors: Department of Marine Biodiversity Research, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima-cho, Yokosuka, Kanagawa, 237-0061, Japan. kato_chi@jamstec.go.jp.
authors: Chiaki
authors: C
authors: Kato
mesh_terms: D050539:3-Isopropylmalate Dehydrogenase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000064:Acclimatization / Q000235:genetics*; D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011312:Pressure; D020592:Shewanella / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D050539:3-Isopropylmalate Dehydrogenase
keywords: Deep-sea enzyme; High pressure; Isopropylmalate dehydrogenase; Molecular adaptation; Water penetration