Mietzsch Mario, Bennett Antonette, McKenna Robert
Department of Biochemistry and Molecular Biology, College of Medicine, Center for Structural Biology, McKnight Brain Institute, University of Florida, Gainesville, FL 32610, USA.
Viruses. 2025 Feb 27;17(3):333. doi: 10.3390/v17030333.
Single-stranded DNA (ssDNA) viruses are a diverse group of pathogens with broad host range, including bacteria, archaea, protists, fungi, plants, invertebrates, and vertebrates. Their small compact genomes have evolved to encode multiple proteins. This review focuses on the structure and functional diversity of the icosahedral capsids across the ssDNA viruses. To date, X-ray crystallography and cryo-electron microscopy structural studies have provided detailed capsid architectures for 8 of the 35 ssDNA virus families, illustrating variations in assembly mechanisms, symmetry, and structural adaptations of the capsid. However, common features include the conserved jelly-roll motif of the capsid protein and strategies for genome packaging, also showing evolutionary convergence. The ever-increasing availability of genomic sequences of ssDNA viruses and predictive protein modeling programs, such as using AlphaFold, allows for the extension of structural insights to the less-characterized families. Therefore, this review is a comparative analysis of the icosahedral ssDNA virus families and how the capsid proteins are arranged with different tessellations to form icosahedral spheres. It summarizes the current knowledge, emphasizing gaps in the structural characterization of the ssDNA capsidome, and it underscores the importance of continued exploration to understand the molecular underpinnings of capsid function and evolution. These insights have implications for virology, molecular biology, and therapeutic applications.
单链DNA（ssDNA）病毒是一类多样的病原体，宿主范围广泛，包括细菌、古菌、原生生物、真菌、植物、无脊椎动物和脊椎动物。它们紧凑的小基因组已经进化到能够编码多种蛋白质。本综述聚焦于ssDNA病毒中二十面体衣壳的结构和功能多样性。迄今为止，X射线晶体学和冷冻电子显微镜结构研究已经为35个ssDNA病毒科中的8个提供了详细的衣壳结构，阐明了衣壳在组装机制、对称性和结构适应性方面的差异。然而，共同特征包括衣壳蛋白保守的果冻卷基序以及基因组包装策略，这也显示出进化趋同。ssDNA病毒基因组序列和预测性蛋白质建模程序（如使用AlphaFold）的可得性不断增加，使得结构见解能够扩展到特征较少的病毒科。因此，本综述是对二十面体ssDNA病毒科以及衣壳蛋白如何通过不同的镶嵌排列形成二十面体球体的比较分析。它总结了当前的知识，强调了ssDNA衣壳组结构表征方面的差距，并强调了持续探索以理解衣壳功能和进化的分子基础的重要性。这些见解对病毒学、分子生物学和治疗应用具有重要意义。
