Broyles S S
Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907-1153.
Virology. 1993 Aug;195(2):863-5. doi: 10.1006/viro.1993.1446.
The sequence of the vaccinia virus open reading frame F2L predicts a polypeptide with significant similarity to cellular dUTPases. To determine whether the F2L gene product has this activity, it was expressed in bacteria as a fusion with glutathione S-transferase. Affinity purified fusion protein was shown to hydrolyze dUTP yielding dUMP as the product. While the dUTPase was not completely dependent on the addition of divalent cations, its activity was stimulated markedly by Zn2+, Mg2+, and Mn2+. The nucleotide substrate specificity of the enzyme was limited to dUTP. These results demonstrate that vaccinia virus encodes a functional dUTPase whose role in viral infection is suggested to be the augmentation of DNA nucleotide precursors and the minimization of cytoplasmic dUTP concentrations.
痘苗病毒开放阅读框F2L的序列预测其编码的多肽与细胞dUTP酶具有显著相似性。为了确定F2L基因产物是否具有这种活性，该基因在细菌中作为与谷胱甘肽S-转移酶的融合蛋白进行表达。亲和纯化的融合蛋白显示能够水解dUTP，产生dUMP作为产物。虽然该dUTP酶并不完全依赖于二价阳离子的添加，但其活性受到Zn2+、Mg2+和Mn2+的显著刺激。该酶的核苷酸底物特异性仅限于dUTP。这些结果表明，痘苗病毒编码一种功能性dUTP酶，其在病毒感染中的作用被认为是增加DNA核苷酸前体并使细胞质dUTP浓度最小化。
