Recombinant pseudorabies virus DNase exhibits a RecBCD-like catalytic function
Recombinant pseudorabies virus DNase exhibits a RecBCD-like catalytic function
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DOI：
10.1042/bj3300055
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发表时间：
1998-02-15
影响因子：
4.1
通讯作者：
Chang, TJ
中科院分区：
文献类型：
--
作者：
Hsiang, CY;Ho, TY;Chang, TJ
伪狂犬病病毒（PRV）DNA酶基因先前已被定位在PRV基因组内。为了进一步表征PRV DNA酶的酶学性质，使用pET表达载体在大肠杆菌中表达该酶。将蛋白质纯化至均一并在体外测定核酸酶活性。重组PRV DNA酶表现出碱性pH偏好和对Mg 2+离子的绝对需求，不能被Ca 2+和Na+离子取代。进一步的研究表明，PRV DNase对单链和双链DNA均具有内切酶、5 ′-外切酶和3 ′-外切酶活性。PRV DNase的多种生化活性与粗糙脉孢菌内切核酸酶和E.大肠杆菌RecBCD，两个额外的酶参与重组。综合考虑，N. crassa内切核酸酶、E. coli RecBCD中表达，而PRV DNA酶的表达则表明PRV DNA酶可能在PRV感染过程中的重组过程中发挥作用。
The pseudorabies virus (PRV) DNase gene has previously been mapped within the PRV genome. To characterize further the enzymic properties of PRV DNase, this enzyme was expressed in Escherichia coli with the use of a pET expression vector. The protein was purified to homogeneity and assayed for nuclease activity in vitro. Recombinant PRV DNase exhibited an alkaline pH preference and an absolute requirement for Mg2+ ions that could not be replaced by Ca2+ and Na+ ions. Further studies showed that PRV DNase exhibited endonuclease, 5'-exonuclease and 3'-exonuclease activities in both single-stranded and double-stranded DNA. This activity occurred randomly and no significant base preference was demonstrated, The multiple biochemical activities of PRV DNase are similar to the activities of Neurospora crassa endo-exonuclease and E. coli RecBCD, two additional enzymes that are involved in recombination. Taken together, the similarity of action between N. crassa endo-exonuclease, E. coli RecBCD, and PRV DNase suggests that PRV DNase might have a role in the process of recombination that occurs during PRV infection.