The catalytic properties of the recombinant reverse transcriptase of bovine immunodeficiency virus
The catalytic properties of the recombinant reverse transcriptase of bovine immunodeficiency virus
复制标题
DOI：
10.1016/j.virol.2006.03.012
复制
发表时间：
2006-07-20
期刊：
影响因子：
3.7
通讯作者：
Hizi, Amnon
中科院分区：
文献类型：
--
作者：
Avidan, Orna;Bochner, Ron;Hizi, Amnon
牛免疫缺陷病毒（BIV）是一种慢病毒，在感染的牛中没有被证实的致病性。然而，在实验感染的兔子中，它会导致类似艾滋病的疾病。因此，我们表达了两种重组亚型的BIV逆转录酶（RT），这在他们的C-末端不同，并研究了它们的催化性能。这两种异构体更喜欢Mg+2超过Mn+2与大多数DNA聚合酶和核糖核酸酶-H底物。BIV RT的DNA合成的持续合成能力高于HIV-1 RT，而合成的保真度甚至低于HIV-1酶。核糖核酸酶-H切割模式表明，两种BIV RT亚型的聚合酶和核糖核酸酶-H活性位点之间的空间距离等于20 nt，而不像在几乎所有其他RT中观察到的17 nt距离。较长的BIV RT版本比较短的版本活性稍低，表明额外的74个残基（与dUTPases同源）可能会阻碍有效的催化。(c)2006年爱思唯尔公司All rights reserved.
Bovine immunodeficiency virus (BIV) is a lentivirus with no proven pathogenesis in infected cattle. Yet, in experimentally infected rabbits, it causes an AIDS-like disease. Consequently, we expressed two recombinant isoforms of BIV reverse transcriptase (RT), which differ in their C-termini, and studied their catalytic properties. Both isoforms prefer Mg+2 over Mn+2 with most DNA polymerase and ribonuclease-H substrates. The processivity of DNA synthesis by the BIV RTs is higher than that of HIV-1 RT, whereas the fidelity of synthesis is even lower than that of the HIV-1 enzyme. The ribonuclease-H cleavage pattern suggests that the spatial distance between the polymerase and ribonuclease-H active sites of the two BIV RT isoforms equals 20 nt, unlike the 17 nt distance observed in almost all other RTs. The longer BIV RT version is somewhat less active than the shorter version, suggesting that the extra 74 residues (with homology to dUTPases) might obstruct efficient catalysis. (c) 2006 Elsevier Inc. All rights reserved.