Residue 134 determines the dimer-tetramer assembly of nucleoside diphosphate kinase from moderately halophilic bacteria.
Halomonas nucleoside diphosphate kinase (HaNDK) forms a dimeric assembly and Pseudomonas NDK (PaNDK) forms a tetrameric assembly. The mutation of Glu134 to Ala in HaNDK resulted in the conversion of the native dimeric structure to the tetramer assembly. Conversely, the mutation of Ala134 to Glu in PaNDK lead to the conversion from the tetramer to the dimer assembly, indicating that a single amino acid substitution at position 134 results in an alteration of the oligomeric structure of NDK. By modeling the structure of HaNDK and PaNDK based on the crystal structure of Myxococcus NDK, we showed that Glu134 exerts sufficient repulsive forces to disrupt the dimer-dimer interaction and prevent the formation of the tetramer.
Tokunaga
Hiroko
H
Applied and Molecular Microbiology, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan. tokunaga@chem.agri.kagoshima-u.ac.jp
Ishibashi
Matsujiro
M
Arisaka
Fumio
F
Arai
Shigeki
S
Kuroki
Ryota
R
Arakawa
Tsutomu
T
Tokunaga
Masao
M
D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D019281:Dimerization; D020632:Halomonas / Q000201:enzymology; D008958:Models, Molecular; D009701:Nucleoside-Diphosphate Kinase / Q000737:chemistry* / Q000235:genetics; D021122:Protein Subunits / Q000737:chemistry; D011549:Pseudomonas / Q000201:enzymology
D001426:Bacterial Proteins; D021122:Protein Subunits; D009701:Nucleoside-Diphosphate Kinase