A distinguishing morphological feature of all herpesviruses is the multiprotein tegument layer located between the nucleocapsid and lipid envelope of the virion. Tegument proteins play multiple roles in viral replication, including viral assembly, but we do not yet understand their individual functions or how the tegument is assembled and organized. UL11, the smallest tegument protein, is important for several distinct processes in replication, including efficient virion morphogenesis and cell-cell spread. However, the mechanistic understanding of its role in these and other processes is limited in part by the scant knowledge of its biochemical and structural properties. Here, we report that UL11 from herpes simplex virus 1 (HSV-1) is an intrinsically disordered, conformationally dynamic protein that undergoes liquid-liquid phase separation (LLPS) in vitro. Intrinsic disorder may underlie the ability of UL11 to exert multiple functions and bind multiple partners. Sequence analysis suggests that not only all UL11 homologs but also all HSV-1 tegument proteins contain intrinsically disordered regions of different lengths. The presence of intrinsic disorder, and potentially, the ability to form LLPS, may thus be a common feature of the tegument proteins. We hypothesize that tegument assembly may involve the formation of a biomolecular condensate, driven by the heterogeneous mixture of intrinsically disordered tegument proteins.

中文翻译：

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单纯疱疹病毒1的保守外皮成分UL11是一种固有的RNA结合蛋白。

所有疱疹病毒的一个明显的形态学特征是位于病毒颗粒的核衣壳和脂质包膜之间的多蛋白外皮层。皮膜蛋白在病毒复制中起多种作用，包括病毒装配，但我们尚不了解它们的个别功能或皮膜的组装和组织方式。UL11是最小的外皮蛋白，对于复制中的几个不同过程至关重要，包括有效的病毒体形态发生和细胞扩散。然而，对其在这些和其他过程中作用的机理的机械理解部分地由于对其生化和结构特性的了解不足而受到限制。在这里，我们报告说，来自单纯疱疹病毒1（HSV-1）的UL11是一种内在无序的，构象动态的蛋白质，它经历了液-液相分离（LLPS）体外。固有疾病可能是UL11发挥多种功能并结合多个伴侣的能力的基础。序列分析表明，不仅所有UL11同源物，而且所有HSV-1皮层蛋白均包含不同长度的内在无序区域。因此，内在疾病的存在以及潜在的形成LLPS的能力可能是外皮蛋白的共同特征。我们假设，由内在无序的外皮蛋白质的异质混合物驱动外皮组装可能涉及生物分子缩合物的形成。