Steinhauer D A, Domingo E, Holland J J
Department of Biology, University of California, San Diego, La Jolla 92093-0116.
Gene. 1992 Dec 15;122(2):281-8. doi: 10.1016/0378-1119(92)90216-c.
The in vitro fidelity of the virion-associated RNA polymerase of vesicular stomatitis virus was quantitated for a single conserved viral RNA site and the usual high in vitro base misincorporation error frequencies (approx. 10(-3)) were observed at this (guanine) site. We sought evidence for RNA 3'-->5' exonuclease proofreading mechanisms by varying the concentrations of the next nucleoside triphosphate, by incorporation of nucleoside[1-thio]triphosphate analogues of the four natural RNA nucleosides, and by varying the concentrations of pyrophosphate in the in vitro polymerase reaction. None of these perturbations greatly affected viral RNA polymerase fidelity at the site studied. These results fail to show evidence for proofreading exonuclease activity associated with the virion replicase of an RNA virus. They suggest that RNA virus replication might generally be error-prone, because RNA replicase base misincorporations are proofread very inefficiently or not at all.
对水疱性口炎病毒的病毒粒子相关RNA聚合酶在体外的保真度进行了定量分析，针对一个单一保守的病毒RNA位点，在该（鸟嘌呤）位点观察到了通常较高的体外碱基错掺入错误频率（约10^(-3)）。我们通过改变下一个核苷三磷酸的浓度、掺入四种天然RNA核苷的核苷[1-硫代]三磷酸类似物以及改变体外聚合酶反应中焦磷酸的浓度，来寻找RNA 3'→5'外切核酸酶校对机制的证据。这些干扰均未对所研究位点的病毒RNA聚合酶保真度产生重大影响。这些结果未能显示出与RNA病毒的病毒粒子复制酶相关的校对外切核酸酶活性的证据。它们表明RNA病毒复制通常可能容易出错，因为RNA复制酶碱基错掺入的校对效率非常低或根本没有校对。
