Dimeric structure of nucleoside diphosphate kinase from moderately halophilic bacterium: contrast to the tetrameric Pseudomonas counterpart |
| |
Authors: | Yonezawa Yasushi Izutsu Ken-ichi Tokunaga Hiroko Maeda Hirotaka Arakawa Tsutomu Tokunaga Masao |
| |
Affiliation: | Applied and Molecular Microbiology, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan. |
| |
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. |
| |
Keywords: | nucleoside diphosphate kinase halophilic Halomonas Pseudomonas dimer subunit |
本文献已被 PubMed 等数据库收录! |
|