Oligomeric structure of nucleoside diphosphate kinase from Halomonas sp.593 (HaNDK)

Arai, Shigeki; Yonezawa, Yasushi; Okazaki, Nobuo; Tamada, Taro; Tokunaga, Hiroko*; Ishibashi, Matsujiro*; Tokunaga, Masao*; Kuroki, Ryota

The nucleoside diphosphate kinases (NDKs) are known to have a tetrameric or hexameric oligomer structure formed by association of common dimeric components. We determined the crystal structure of E134A mutant NDK from sp. 593 (HaNDK) and found that two kinds of tetrameric assemblies, Type I seen in the NDK tetramer and Type II seen in the NDK tetramer, appeared in the asymmetric unit. Change in the assembly form may be an effective way for NDK to acquire molecular characteristics suited to various circumstances.