The structure of the Escherichia coli nucleoside diphosphate kinase reveals a new quaternary architecture for this enzyme family.
Nucleoside diphosphate kinase (NDPK) catalyzes the transfer of gamma-phosphate from nucleoside triphosphates to nucleoside diphosphates. The subunit folding and the dimeric basic structural unit are remarkably the same for available structures but, depending on species, dimers self-associate to form hexamers or tetramers. The crystal structure of the Escherichia coli NDPK reveals a new tetrameric quaternary structure for this protein family. The two tetramers differ by the relative orientation of interacting dimers, which face either the convex or the concave side of their central sheet as in either Myxococcus xanthus (type I) or E. coli (type II), respectively. In the type II tetramer, the subunits interact by a new interface harboring a zone called the Kpn loop as in hexamers, but by the opposite face of this loop. The evolutionary conservation of the interface residues indicates that this new quaternary structure seems to be the most frequent assembly mode in bacterial tetrameric NDP kinases.
Moynié
Lucile
L
Institut de Biochimie et Génétique Cellulaires, UMR 5095 CNRS-Université Victor Segalen Bordeaux 2, 33077 Bordeaux cedex, France.
Giraud
Marie-France
MF
Georgescauld
Florian
F
Lascu
Ioan
I
Dautant
Alain
A
D000595:Amino Acid Sequence; D018360:Crystallography, X-Ray / Q000379:methods; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009701:Nucleoside-Diphosphate Kinase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
D029968:Escherichia coli Proteins; D009701:Nucleoside-Diphosphate Kinase