美国加州大学洛杉矶分校Z. Hong Zhou研究组和Ren Sun研究组合作报道了肿瘤疱疹病毒KSHV中的DNA包装门户和衣壳相关的被膜复合物结构。2019年8月22日，相关论文在线发表在《细胞》上。

使用对称松弛冷冻电镜，研究人员确定了KSHV门户的原位结构及其与周围衣壳蛋白、CATC和KSHV双链DNA基因组末端的相互作用。门户和衣壳/CATC的原子模型，以及CATC的可变占据和CATC相互作用的顶点三链体的交替方向的可视化，为门户在DNA包装过程中协调前衣壳形成和CATC不对称附着提出了一种机制。基于结构的诱变实验证实，CATC的三重深层结合沟是一个有望开展抗病毒治疗的热点区域。

据介绍，Kaposi肉瘤相关疱疹病毒（KSHV）的组装开始于一个类似噬菌体的门户复合物，它使形成具有衣壳相关的外壳复合物（CATC）的二十面体衣壳成核并促进大约150kb长度双链DNA基因组的转移，然后获得多形的被膜和外壳。由于偏离二十面体对称性，KSHV门户和被膜结构在以前的研究中无法看清。

附：英文原文

Title: DNA-Packing Portal and Capsid-Associated Tegument Complexes in the Tumor Herpesvirus KSHV

Author: Danyang Gong, Xinghong Dai, Jonathan Jih, Yun-Tao Liu, Guo-Qiang Bi, Ren Sun, Z. Hong Zhou

Issue&Volume: 22 August 2019

Abstract: Assembly of Kaposi’s sarcoma-associated herpesvirus (KSHV) begins at a bacteriophage-like portal complex that nucleates formation of an icosahedral capsid with capsid-associated tegument complexes (CATCs) and facilitates translocation of an ～150-kb dsDNA genome, followed by acquisition of a pleomorphic tegument and envelope. Because of deviation from icosahedral symmetry, KSHV portal and tegument structures have largely been obscured in previous studies. Using symmetry-relaxed cryo-EM, we determined the in situ structure of the KSHV portal and its interactions with surrounding capsid proteins, CATCs, and the terminal end of KSHV’s dsDNA genome. Our atomic models of the portal and capsid/CATC, together with visualization of CATCs’ variable occupancy and alternate orientation of CATC-interacting vertex triplexes, suggest a mechanism whereby the portal orchestrates procapsid formation and asymmetric long-range determination of CATC attachment during DNA packaging prior to pleomorphic tegumentation/envelopment. Structure-based mutageneses confirm that a triplex deep binding groove for CATCs is a hotspot that holds promise for antiviral development.

DOI: https://doi.org/10.1016/j.cell.2019.07.035

Source: https://www.cell.com/cell/fulltext/S0092-8674(19)30834-7#