Spurny Radovan, Přidal Antonín, Pálková Lenka, Kiem Hoa Khanh Tran, de Miranda Joachim R, Plevka Pavel
Structural Virology, Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
Department of Zoology, Fishery, Hydrobiology, and Apidology, Faculty of Agronomy, Mendel University in Brno, Brno, Czech Republic.
J Virol. 2017 Feb 28;91(6). doi: 10.1128/JVI.02100-16. Print 2017 Mar 15.
Viral diseases are a major threat to honeybee () populations worldwide and therefore an important factor in reliable crop pollination and food security. Black queen cell virus (BQCV) is the etiological agent of a fatal disease of honeybee queen larvae and pupae. The virus belongs to the genus from the family , which is part of the order Here we present a crystal structure of BQCV determined to a resolution of 3.4 Å. The virion is formed by 60 copies of each of the major capsid proteins VP1, VP2, and VP3; however, there is no density corresponding to a 75-residue-long minor capsid protein VP4 encoded by the BQCV genome. We show that the VP4 subunits are present in the crystallized virions that are infectious. This aspect of the BQCV virion is similar to that of the previously characterized triatoma virus and supports the recent establishment of the separate genus within the family The C terminus of VP1 and CD loops of capsid proteins VP1 and VP3 of BQCV form 34-Å-tall finger-like protrusions at the virion surface. The protrusions are larger than those of related dicistroviruses. The western honeybee is the most important pollinator of all, and it is required to sustain the agricultural production and biodiversity of wild flowering plants. However, honeybee populations worldwide are suffering from virus infections that cause colony losses. One of the most common, and least known, honeybee pathogens is black queen cell virus (BQCV), which at high titers causes queen larvae and pupae to turn black and die. Here we present the three-dimensional virion structure of BQCV, determined by X-ray crystallography. The structure of BQCV reveals large protrusions on the virion surface. Capsid protein VP1 of BQCV does not contain a hydrophobic pocket. Therefore, the BQCV virion structure provides evidence that capsid-binding antiviral compounds that can prevent the replication of vertebrate picornaviruses may be ineffective against honeybee virus infections.
病毒性疾病是全球蜜蜂种群面临的主要威胁，因此是可靠的作物授粉和粮食安全的一个重要因素。黑蜂王台病毒（BQCV）是蜜蜂蜂王幼虫和蛹致命疾病的病原体。该病毒属于 科的 属，该科是 目的一部分。在此，我们展示了分辨率为3.4 Å的BQCV晶体结构。病毒粒子由主要衣壳蛋白VP1、VP2和VP3各60个拷贝组成；然而，没有与BQCV基因组编码的75个残基长的次要衣壳蛋白VP4相对应的密度。我们表明VP4亚基存在于具有感染性的结晶病毒粒子中。BQCV病毒粒子的这一方面与先前表征的锥蝽病毒相似，并支持最近在 科内建立单独的 属。BQCV的VP1的C末端以及衣壳蛋白VP1和VP3的CD环在病毒粒子表面形成34 Å高的手指状突起。这些突起比相关双顺反子病毒的突起更大。西方蜜蜂是所有蜜蜂中最重要的传粉者，维持农业生产和野生开花植物的生物多样性需要它。然而，全球蜜蜂种群正遭受导致蜂群损失的病毒感染。最常见且最不为人知的蜜蜂病原体之一是黑蜂王台病毒（BQCV），高滴度时会导致蜂王幼虫和蛹变黑并死亡。在此，我们展示了通过X射线晶体学确定的BQCV三维病毒粒子结构。BQCV的结构揭示了病毒粒子表面的大突起。BQCV的衣壳蛋白VP1不包含疏水口袋。因此，BQCV病毒粒子结构提供了证据，表明可防止脊椎动物微小核糖核酸病毒复制的衣壳结合抗病毒化合物可能对蜜蜂病毒感染无效。
