title: Structural analysis of 3-isopropylmalate dehydrogenase from the obligate piezophile Shewanella benthica DB21MT-2 and the nonpiezophile Shewanella oneidensis MR-1.
abstract: Organisms living in deep seas such as the Mariana Trench must be adapted to the extremely high pressure environment. For example, the 3-isopropylmalate dehydrogenase from the obligate piezophile Shewanella benthica DB21MT-2 (SbIPMDH) remains active in extreme conditions under which that from the land bacterium S. oneidensis MR-1 (SoIPMDH) becomes inactivated. In order to unravel the differences between these two IPMDHs, their structures were determined at ~1.5 Å resolution. Comparison of the structures of the two enzymes shows that SbIPMDH is in a more open form and has a larger internal cavity volume than SoIPMDH at atmospheric pressure. This loosely packed structure of SbIPMDH could help it to avoid pressure-induced distortion of the native structure and to remain active at higher pressures than SoIPMDH.
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Nagoya University, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nagae
authors.forename: Chiaki
authors.initials: C
authors.lastname: Kato
authors.forename: Nobuhisa
authors.initials: N
authors.lastname: Watanabe
mesh_terms: D050539:3-Isopropylmalate Dehydrogenase / Q000737:chemistry*; D008958:Models, Molecular; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D020592:Shewanella / Q000201:enzymology*; D040681:Structural Homology, Protein
chemical_list: D050539:3-Isopropylmalate Dehydrogenase