PDF(Pubmed)
Abstract：
SETD3 is an essential host factor for the replication of a variety of enteroviruses that specifically interacts with viral protease 2A. However, the interaction between SETD3 and the 2A protease has not been fully characterized. Here, we use X-ray crystallography and cryo-electron microscopy to determine the structures of SETD3 complexed with the 2A protease of EV71 to 3.5 Å and 3.1 Å resolution, respectively. We find that the 2A protease occupies the V-shaped central cleft of SETD3 through two discrete sites. The relative positions of the two proteins vary in the crystal and cryo-EM structures, showing dynamic binding. A biolayer interferometry assay shows that the EV71 2A protease outcompetes actin for SETD3 binding. We identify key 2A residues involved in SETD3 binding and demonstrate that 2A\'s ability to bind SETD3 correlates with EV71 production in cells. Coimmunoprecipitation experiments in EV71 infected and 2A expressing cells indicate that 2A interferes with the SETD3-actin complex, and the disruption of this complex reduces enterovirus replication. Together, these results reveal the molecular mechanism underlying the interplay between SETD3, actin, and viral 2A during virus replication.
摘要：
SETD3是与病毒蛋白酶2A特异性相互作用的多种肠道病毒复制的必需宿主因子。然而,SETD3和2A蛋白酶之间的相互作用尚未得到充分表征。这里,我们使用X射线晶体学和低温电子显微镜来确定与EV71的2A蛋白酶复合的SETD3的结构，分辨率为3.5和3.1，分别。我们发现2A蛋白酶通过两个离散位点占据了SETD3的V形中央裂口。两种蛋白质的相对位置在晶体和低温-EM结构中有所不同，显示动态绑定。生物层干涉测定表明，EV712A蛋白酶超过肌动蛋白与SETD3的结合。我们鉴定了参与SETD3结合的关键2A残基，并证明2A结合SETD3的能力与细胞中EV71的产生相关。在EV71感染和2A表达细胞中的免疫共沉淀实验表明2A干扰SETD3-肌动蛋白复合物，这种复合物的破坏减少了肠道病毒的复制。一起,这些结果揭示了SETD3、肌动蛋白、和病毒2A在病毒复制过程中。
