Shanghai Public Health Clinical Center, State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China.
State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China.
Nucleic Acids Res. 2023 Sep 22;51(17):9475-9490. doi: 10.1093/nar/gkad677.
African swine fever virus (ASFV) is highly contagious and can cause lethal disease in pigs. Although it has been extensively studied in the past, no vaccine or other useful treatment against ASFV is available. The genome of ASFV encodes more than 170 proteins, but the structures and functions for the majority of the proteins remain elusive, which hindered our understanding on the life cycle of ASFV and the development of ASFV-specific inhibitors. Here, we report the structural and biochemical studies of the highly conserved C962R protein of ASFV, showing that C962R is a multidomain protein. The N-terminal AEP domain is responsible for the DNA polymerization activity, whereas the DNA unwinding activity is catalyzed by the central SF3 helicase domain. The middle PriCT2 and D5_N domains and the C-terminal Tail domain all contribute to the DNA unwinding activity of C962R. C962R preferentially works on forked DNA, and likely functions in Base-excision repair (BER) or other repair pathway in ASFV. Although it is not essential for the replication of ASFV, C962R can serve as a model and provide mechanistic insight into the replicative primase proteins from many other species, such as nitratiruptor phage NrS-1, vaccinia virus (VACV) and other viruses.
非洲猪瘟病毒（ASFV）具有高度传染性，可导致猪的致命疾病。尽管过去对其进行了广泛研究，但目前尚无针对 ASFV 的疫苗或其他有效治疗方法。ASFV 的基因组编码了 170 多种蛋白质，但大多数蛋白质的结构和功能仍然难以捉摸，这阻碍了我们对 ASFV 生命周期和 ASFV 特异性抑制剂开发的理解。在这里，我们报告了 ASFV 高度保守的 C962R 蛋白的结构和生化研究，结果表明 C962R 是一种多结构域蛋白。N 端 AEP 结构域负责 DNA 聚合酶活性，而中央 SF3 解旋酶结构域催化 DNA 解旋活性。中间的 PriCT2 和 D5_N 结构域以及 C 端尾部结构域都有助于 C962R 的 DNA 解旋活性。C962R 优先作用于分叉 DNA，可能在 ASFV 的碱基切除修复（BER）或其他修复途径中发挥作用。尽管它对 ASFV 的复制不是必需的，但 C962R 可以作为一个模型，为来自许多其他物种的复制起始酶蛋白提供机制上的见解，例如 nitratiruptor 噬菌体 NrS-1、牛痘病毒（VACV）和其他病毒。
