The vaccinia virus D5 protein, which is required for DNA replication, is a nucleic acid-independent nucleoside triphosphatase.
The vaccinia virus D5 gene encodes a 90-kDa protein that is transiently expressed at early times after infection. Temperature-sensitive mutants with lesions in the D5 gene exhibit a fast-stop DNA- phenotype and are also impaired in homologous recombination. Here we report the overexpression of the D5 protein within the context of a vaccinia virus infection and its purification to apparent homogeneity. The purified protein has an intrinsic nucleoside triphosphatase activity which is independent of, and not stimulated by, any common nucleic acid cofactors. All eight common ribo- and deoxyribonucleoside triphosphates are hydrolyzed to the diphosphate form in the presence of a divalent cation. Implications for the role of D5 in viral DNA replication are addressed.
Evans
E
E
Department of Cell Biology, Cornell University Medical College, New York, New York 10021, USA.
Klemperer
N
N
Ghosh
R
R
Traktman
P
P
D017766:Acid Anhydride Hydrolases / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000302:isolation & purification / Q000378:metabolism; D002460:Cell Line; D002846:Chromatography, Affinity; D002848:Chromatography, DEAE-Cellulose; D004261:DNA Replication; D005814:Genes, Viral; D006801:Humans; D007700:Kinetics; D016296:Mutagenesis; D043583:Nucleoside-Triphosphatase; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D015183:Restriction Mapping; D013696:Temperature; D014162:Transfection; D014616:Vaccinia virus / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*
D011994:Recombinant Proteins; D014764:Viral Proteins; D017766:Acid Anhydride Hydrolases; D000251:Adenosine Triphosphatases; D043583:Nucleoside-Triphosphatase