Chung Y T, Hsu W
Department of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan.
Arch Virol. 1996;141(12):2457-64. doi: 10.1007/BF01718643.
Sequence analysis within the unique long segment of the bovine herpesvirus 1 (BHV-1; infectious bovine rhinotracheitis virus) genome identified an open reading frame whose deduced protein product of 487 amino acids exhibited homology to alkaline deoxyribonucleases (DNases) of other herpesviruses. To determine this BHV-1 gene product has nuclease activity, the gene designated UL12 was inserted into the vector pET-28a(+) and expressed in Escherichia coli as an oligohistidine-tagged protein. Upon induction with isopropyl beta-D-thiogalactopyranoside E. coli BL21 (DE3) [pLysS] cells carrying this recombinant plasmid produced a 57-kDa protein, the molecular mass of which was in accordance with the prediction from the DNA sequence. The recombinant UL12 protein purified by nickel-chelating affinity chromatography exhibited both exonuclease and endonuclease activity, each with an alkaline pH optimum.
对牛疱疹病毒1型（BHV - 1；传染性牛鼻气管炎病毒）基因组独特长片段进行的序列分析，鉴定出一个开放阅读框，其推导的487个氨基酸的蛋白质产物与其他疱疹病毒的碱性脱氧核糖核酸酶（DNase）具有同源性。为了确定该BHV - 1基因产物是否具有核酸酶活性，将命名为UL12的基因插入载体pET - 28a(+) ，并作为带有寡聚组氨酸标签的蛋白质在大肠杆菌中表达。用异丙基β - D - 硫代半乳糖苷诱导后，携带该重组质粒的大肠杆菌BL21(DE3) [pLysS]细胞产生了一种57 kDa的蛋白质，其分子量与DNA序列预测的一致。通过镍螯合亲和层析纯化的重组UL12蛋白同时表现出核酸外切酶和核酸内切酶活性，每种活性的最适pH均为碱性。
