Structural Basis of Poxvirus Transcription: Vaccinia RNA Polymerase Complexes
Structural Basis of Poxvirus Transcription: Vaccinia RNA Polymerase Complexes
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DOI：
10.1016/j.cell.2019.11.024
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发表时间：
2019-12-12
期刊：
影响因子：
64.5
通讯作者：
Fischer, Utz
中科院分区：
文献类型：
--
作者：
Grimm, Clemens;Hillen, Hauke S.;Fischer, Utz
痘病毒编码一种多亚单位DNA依赖的RNA聚合酶(VRNAP)，在宿主细胞质中进行病毒基因的表达。我们报道了痘苗病毒核心和完整vRNAP酶在2.8埃分辨率下的冷冻EM结构。VRNAP核心酶类似于真核RNA聚合酶II(POL II)，但也显示了许多病毒特有的功能，包括转录因子Rap94。完整的酶还含有转录因子VETF、mRNA处理因子VTF/CE和NPH-I、病毒核心蛋白E11和宿主tRNA(Gln)。这个复合体可以完成整个早期转录周期。结构表明，Rap94部分类似于Pol II起始因子TFIIB，vRNAP亚基Rpo30类似于Pol II延伸因子TFIIS，NPH-I类似于染色质重塑酶。与随附的论文(Hillen等人，2019年)一起，这些结果为揭开痘病毒转录和RNA加工的机制提供了基础。
Poxviruses encode a multisubunit DNA-dependent RNA polymerase (vRNAP) that carries out viral gene expression in the host cytoplasm. We report cryoEM structures of core and complete vRNAP enzymes from Vaccinia virus at 2.8 angstrom resolution. The vRNAP core enzyme resembles eukaryotic RNA polymerase II (Pol II) but also reveals many virus-specific features, including the transcription factor Rap94. The complete enzyme additionally contains the transcription factor VETF, the mRNA processing factors VTF/CE and NPH-I, the viral core protein E11, and host tRNA(Gln). This complex can carry out the entire early transcription cycle. The structures show that Rap94 partially resembles the Pol II initiation factor TFIIB, that the vRNAP subunit Rpo30 resembles the Pol II elongation factor TFIIS, and that NPH-I resembles chromatin remodeling enzymes. Together with the accompanying paper (Hillen et al., 2019), these results provide the basis for unraveling the mechanisms of poxvirus transcription and RNA processing.