Unique 5'-P recognition and basis for dG:dGTP misincorporation of ASFV DNA polymerase X.
Unique 5'-P recognition and basis for dG:dGTP misincorporation of ASFV DNA polymerase X.
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独特的 5'-P 识别和 dG 基础：ASFV DNA 聚合酶 X 的 dGTP 错误掺入
DOI：
10.1371/journal.pbio.1002599
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发表时间：
2017-02
期刊：
影响因子：
9.8
通讯作者：
Gan J
中科院分区：
文献类型：
--
作者：
Chen Y;Zhang J;Liu H;Gao Y;Li X;Zheng L;Cui R;Yao Q;Rong L;Li J;Huang Z;Ma J;Gan J
非洲猪瘟病毒（ASFV）可引起猪的高度致命疾病，并正在成为全球威胁。 ASFV DNA 聚合酶 X (AsfvPolX) 是迄今为止发现的最独特的 DNA 聚合酶；它缺乏同源蛋白中保守的两个 DNA 结合域（拇指域和 8-KD 域）。 AsfvPolX在ASFV病毒基因组DNA修复过程中催化间隙填充反应；它非常容易出错，并且在病毒基因组的策略诱变过程中发挥着重要作用。 AsfvPolX 的天然底物结合和最常见的 dG:dGTP 错误掺入的结构基础仍然知之甚少。在这里，我们报告了八种 AsfvPolX 复杂结构；我们的结构表明 AsfvPolX 具有一个独特的 5'-磷酸 (5'-P) 结合口袋，有利于高效催化复合物组装并提高 dGTP 错误掺入效率。结合诱变和体外催化测定，我们的研究还揭示了His115-Arg127平台以及疏水残基Val120和Leu123在dG:dGTP错误掺入中的功能作用，并可以为合理的药物设计提供信息，以帮助将来对抗ASFV。非洲猪瘟病毒基因组编码已知最独特的 DNA 聚合酶 AsfvPolX。结构和功能研究揭示了其策略性错误地将 dGTP 错误掺入 dG 残基的基础。非洲猪瘟病毒（ASFV）具有高度传染性，可导致猪致命。 AsfvPolX在病毒基因组的DNA修复过程中催化间隙填充反应；它非常容易出错，并且在病毒基因组的策略诱变中发挥着重要作用。与同源蛋白不同，AsfvPolX 具有几个独特的结构特征，包括 5′-P 结合口袋、His115-Arg127 平台以及疏水残基 Val120 和 Leu123，这些都会影响 AsfvPolX 的催化效率（特别是在 dG:dGTP 错误掺入期间）。这些特性，特别是5'-P结合口袋，为设计小分子提供了理想的结构基础，可以特异性抑制AsfvPolX的活性并破坏ASFV基因组的DNA修复过程。
African swine fever virus (ASFV) can cause highly lethal disease in pigs and is becoming a global threat. ASFV DNA Polymerase X (AsfvPolX) is the most distinctive DNA polymerase identified to date; it lacks two DNA-binding domains (the thumb domain and 8-KD domain) conserved in the homologous proteins. AsfvPolX catalyzes the gap-filling reaction during the DNA repair process of the ASFV virus genome; it is highly error prone and plays an important role during the strategic mutagenesis of the viral genome. The structural basis underlying the natural substrate binding and the most frequent dG:dGTP misincorporation of AsfvPolX remain poorly understood. Here, we report eight AsfvPolX complex structures; our structures demonstrate that AsfvPolX has one unique 5′-phosphate (5′-P) binding pocket, which can favor the productive catalytic complex assembly and enhance the dGTP misincorporation efficiency. In combination with mutagenesis and in vitro catalytic assays, our study also reveals the functional roles of the platform His115-Arg127 and the hydrophobic residues Val120 and Leu123 in dG:dGTP misincorporation and can provide information for rational drug design to help combat ASFV in the future. The African swine fever virus genome encodes the most distinctive DNA polymerase known, AsfvPolX. A structural and functional study reveals the basis for its strategic error-prone misincorporation of dGTP opposite a dG residue. African swine fever virus (ASFV) is highly contagious and can cause lethal disease in pigs. AsfvPolX catalyzes the gap-filling reaction during the DNA repair process of the virus genome; it is highly error prone and plays an important role in the strategic mutagenesis of the virus genome. Unlike the homologous proteins, AsfvPolX has several unique structural features, including a 5′-P binding pocket, a His115-Arg127 platform, and hydrophobic residues Val120 and Leu123, which can all affect the catalytic efficiency (especially during dG:dGTP misincorporation) of AsfvPolX. These properties, especially the 5′-P binding pocket, provide an ideal structural basis for designing of small molecules, which can specifically inhibit the activity of AsfvPolX and disrupt the DNA repair process of the ASFV genome.