Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
Curr Opin Virol. 2012 Oct;2(5):519-24. doi: 10.1016/j.coviro.2012.07.005. Epub 2012 Aug 1.
RNA virus evolution results from viral replication fidelity and mutational robustness in combination with selection. Recent studies have confirmed the impact of increased fidelity on RNA virus replication and pathogenesis; however, the impact of decreased fidelity is less defined. Coronaviruses have the largest RNA genomes, and encode an exoribonuclease activity that is required for high-fidelity replication. Genetically stable exoribonuclease mutants will allow direct testing of viral mutational tolerance to RNA mutagens and other selective pressures. Recent studies support the hypothesis that coronavirus replication fidelity may result from a multi-protein complex, suggesting multiple pathways to disrupt or alter virus fidelity and diversity, and attenuate pathogenesis.
RNA 病毒的进化是由病毒复制保真度和突变稳定性与选择共同作用的结果。最近的研究证实了提高保真度对 RNA 病毒复制和发病机制的影响；然而，降低保真度的影响则不太明确。冠状病毒具有最大的 RNA 基因组，并编码一种外切核酸酶活性，该活性对于高保真度的复制是必需的。遗传稳定的外切核酸酶突变体将允许直接测试病毒对 RNA 诱变剂和其他选择压力的突变耐受性。最近的研究支持这样一种假设，即冠状病毒复制保真度可能来自于一个多蛋白复合物，这表明有多种途径可以破坏或改变病毒的保真度和多样性，并减轻发病机制。
