title: Dimeric structure of nucleoside diphosphate kinase from moderately halophilic bacterium: contrast to the tetrameric Pseudomonas counterpart.
abstract: Light scattering and chemical cross-linking analyses of nucleoside diphosphate kinase (NDK) from moderate halophile, Halomonas sp. 593 (HaNDK), unambiguously demonstrated that this enzyme formed a dimeric structure, in contrast to the Pseudomonas NDK (PaNDK), a nonhalophilic counterpart, and other NDKs from Gram-negative bacteria, which all formed a tetrameric structure. Comparison of HaNDK and PaNDK showed that the HaNDK was less thermally stable than the PaNDK: the optimum temperature of PaNDK enzyme activity was 20 degrees C higher than that of HaNDK. However, the HaNDK readily refolded and reassembled back to the active dimeric structure, upon heat denaturation at 0.2 M NaCl, as soon as the temperature was lowered. On the contrary, the thermally more stable PaNDK was irreversibly denatured at its melting temperature.
authors.affiliation: Applied and Molecular Microbiology, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Yonezawa
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Izutsu
authors.forename: Hiroko
authors.initials: H
authors.lastname: Tokunaga
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Maeda
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Arakawa
authors.forename: Masao
authors.initials: M
authors.lastname: Tokunaga
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003432:Cross-Linking Reagents; D019281:Dimerization; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D020632:Halomonas / Q000201:enzymology* / Q000254:growth & development; D006358:Hot Temperature; D007700:Kinetics; D009701:Nucleoside-Diphosphate Kinase / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D011489:Protein Denaturation; D011549:Pseudomonas / Q000201:enzymology* / Q000254:growth & development; D012965:Sodium Chloride
chemical_list: D003432:Cross-Linking Reagents; D012965:Sodium Chloride; D009701:Nucleoside-Diphosphate Kinase