Cox Robert, Pickar Adrian, Qiu Shihong, Tsao Jun, Rodenburg Cynthia, Dokland Terje, Elson Andrew, He Biao, Luo Ming
Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294;
Department of Infectious Diseases, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602; and.
Proc Natl Acad Sci U S A. 2014 Oct 21;111(42):15208-13. doi: 10.1073/pnas.1413268111. Epub 2014 Oct 6.
Mumps virus (MuV) is a highly contagious pathogen, and despite extensive vaccination campaigns, outbreaks continue to occur worldwide. The virus has a negative-sense, single-stranded RNA genome that is encapsidated by the nucleocapsid protein (N) to form the nucleocapsid (NC). NC serves as the template for both transcription and replication. In this paper we solved an 18-Å-resolution structure of the authentic MuV NC using cryo-electron microscopy. We also observed the effects of phosphoprotein (P) binding on the MuV NC structure. The N-terminal domain of P (PNTD) has been shown to bind NC and appeared to induce uncoiling of the helical NC. Additionally, we solved a 25-Å-resolution structure of the authentic MuV NC bound with the C-terminal domain of P (PCTD). The location of the encapsidated viral genomic RNA was defined by modeling crystal structures of homologous negative strand RNA virus Ns in NC. Both the N-terminal and C-terminal domains of MuV P bind NC to participate in access to the genomic RNA by the viral RNA-dependent-RNA polymerase. These results provide critical insights on the structure-function of the MuV NC and the structural alterations that occur through its interactions with P.
腮腺炎病毒（MuV）是一种极具传染性的病原体，尽管开展了广泛的疫苗接种运动，但全球仍不断有疫情爆发。该病毒具有负链单链RNA基因组，由核衣壳蛋白（N）包裹形成核衣壳（NC）。NC作为转录和复制的模板。在本文中，我们利用冷冻电子显微镜解析了真实MuV NC的18埃分辨率结构。我们还观察了磷蛋白（P）结合对MuV NC结构的影响。P的N端结构域（PNTD）已被证明可与NC结合，并似乎诱导螺旋状NC解旋。此外，我们解析了与P的C端结构域（PCTD）结合的真实MuV NC的25埃分辨率结构。通过对NC中同源负链RNA病毒Ns的晶体结构进行建模，确定了包裹的病毒基因组RNA的位置。MuV P的N端和C端结构域均与NC结合，参与病毒RNA依赖性RNA聚合酶对基因组RNA的获取。这些结果为MuV NC的结构功能以及通过其与P相互作用发生的结构改变提供了关键见解。
