The nucleoside diphosphate kinase from mimivirus: a peculiar affinity for deoxypyrimidine nucleotides.
The first viral Nucleoside Diphosphate Kinase was recently identified in the giant double-stranded DNA virus Acanthamoeba polyphag a Mimivirus (ApM). Here we report its expression and detailed biochemical characterization. NDK(apm) exhibits unique features such as a shorter Kpn-loop, a structural motif previously reported to be part of the active site and involved in oligomer formation. Enzymatic activity measurements on the recombinant NDK(apm) revealed its preferential affinity for deoxypyrimidine nucleotides. This property might represent an adaptation of NDK(apm) to the production of the limiting TTP deoxynucleotide required for the replication of the large A+T rich (72%) viral genome. The NDK(apm) might also assume a role in dUTP detoxification to compensate for the surprising absence of Mimivirus dUTPase (deoxyuridine triphosphate pyrophosphatase) an important enzyme conserved in most viruses. Although the phylogenetic analysis of NDK sequences sampled through organisms from the three domains of life is only partially informative, it favors an ancestral origin for NDK(apm) over a recent acquisition from a eukaryotic organism by horizontal gene transfer.
Jeudy
Sandra
S
Information Génomique & Structurale, CNRS UPR 2589, IBSM, 163 Avenue de Luminy, 13288, Marseille cedex 9, France.
Claverie
Jean-Michel
JM
Abergel
Chantal
C
D000048:Acanthamoeba / Q000821:virology*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004267:DNA Viruses / Q000201:enzymology*; D007700:Kinetics; D008969:Molecular Sequence Data; D009701:Nucleoside-Diphosphate Kinase / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D011743:Pyrimidines / Q000378:metabolism; D017422:Sequence Analysis, DNA
D011743:Pyrimidines; D009701:Nucleoside-Diphosphate Kinase