Cryo-EM Structure of Gokushovirus ΦEC6098 Reveals a Novel Capsid Architecture for a Single-Scaffolding Protein, Microvirus Assembly System
Cryo-EM Structure of Gokushovirus ΦEC6098 Reveals a Novel Capsid Architecture for a Single-Scaffolding Protein, Microvirus Assembly System
复制标题
Gokushovirus δ EC6098 的冷冻电镜结构揭示了单支架蛋白、微病毒组装系统的新型衣壳结构
DOI：
10.1128/jvi.00990-22
复制
发表时间：
2022
影响因子：
5.4
通讯作者：
Hafenstein, Susan L.
中科院分区：
文献类型：
--
作者：
Lee, Hyunwook;Baxter, Alexis J.;Bator, Carol M.;Fane, Bentley A.;Hafenstein, Susan L.
在生态系统和微生物组中普遍存在和丰富，戈舒病毒构成微病毒亚科，与噬菌体ΦX174，α3和G4有较远的关系。测定了谷口病毒Φ EC 6098的高分辨冷冻电镜结构，并重新建立了原子模型。虽然戈库索病毒缺乏与ΦX174衣壳蛋白广泛相互作用的外部支架和刺突蛋白，但Φ EC 6098外壳蛋白（VP 1）的核心显示出类似的结构。然而，存在着关键的区别。在每个Φ EC 6098二十面体3重轴处，长插入环形成蘑菇状突起，这在较低分辨率的gokushovirus结构中已经注意到。这些突起底部的疏水界面可以赋予衣壳壳稳定性。在ΦX174中，衣壳蛋白的N-末端直接位于3倍对称轴的顶部;然而，Φ EC 6098 N-末端延伸穿过衣壳壳的内表面，几乎到达相邻五聚体的5倍轴。因此，这种延伸的N-末端在衣壳壳内部互连五聚体，推测促进衣壳组装，这是由ΦX174外部支架蛋白执行的功能。ΦX174样DNA结合J蛋白与其Φ EC 6098同源物VP 8之间也存在关键差异。如J蛋白所见，C-末端VP 8残基结合到主要衣壳蛋白内的口袋中;然而，其N-末端残基是无序的，可能是由于柔性。我们发现，VP 8的C-末端和VP 1的N-末端的一部分的组合的位置和相互作用是与ΦX174和α3 J蛋白所看到的那些令人想起。已被充分研究的ΦX174样病毒在其二十面体顶点处具有突出的刺突，这在gokushoviruses中不存在。相反，戈库索病毒的主要外壳蛋白在3重对称轴上形成广泛的蘑菇状突起。此外，戈库舒病毒缺乏外部支架蛋白，这是两种ΦX174组装蛋白中更关键的，但保留了内部支架蛋白。Φ EC 6098病毒粒子表明，关键的外部支架功能可能是由戈库什病毒特有的外壳蛋白结构域执行的。因此，在一个家族中，不同的组装路径已经被采用，这表明了两个支架蛋白质系统如何演变成一个支架蛋白质系统，反之亦然。
Ubiquitous and abundant in ecosystems and microbiomes, gokushoviruses constitute aMicroviridaesubfamily, distantly related to bacteriophages ΦX174, α3, and G4. A high-resolution cryo-EM structure of gokushovirus ΦEC6098 was determined, and the atomic model was builtde novo. Although gokushoviruses lack external scaffolding and spike proteins, which extensively interact with the ΦX174 capsid protein, the core of the ΦEC6098 coat protein (VP1) displayed a similar structure. There are, however, key differences. At each ΦEC6098 icosahedral 3-fold axis, a long insertion loop formed mushroom-like protrusions, which have been noted in lower-resolution gokushovirus structures. Hydrophobic interfaces at the bottom of these protrusions may confer stability to the capsid shell. In ΦX174, the N-terminus of the capsid protein resides directly atop the 3-fold axes of symmetry; however, the ΦEC6098 N-terminus stretched across the inner surface of the capsid shell, reaching nearly to the 5-fold axis of the neighboring pentamer. Thus, this extended N-terminus interconnected pentamers on the inside of the capsid shell, presumably promoting capsid assembly, a function performed by the ΦX174 external scaffolding protein. There were also key differences between the ΦX174-like DNA-binding J proteins and its ΦEC6098 homologue VP8. As seen with the J proteins, C-terminal VP8 residues were bound into a pocket within the major capsid protein; however, its N-terminal residues were disordered, likely due to flexibility. We show that the combined location and interaction of VP8’s C-terminus and a portion of VP1’s N-terminus are reminiscent of those seen with the ΦX174 and α3 J proteins.IMPORTANCEThere is a dramatic structural and morphogenetic divide within theMicroviridae. The well-studied ΦX174-like viruses have prominent spikes at their icosahedral vertices, which are absent in gokushoviruses. Instead, gokushovirus major coat proteins form extensive mushroom-like protrusions at the 3-fold axes of symmetry. In addition, gokushoviruses lack an external scaffolding protein, the more critical of the two ΦX174 assembly proteins, but retain an internal scaffolding protein. The ΦEC6098 virion suggests that key external scaffolding functions are likely performed by coat protein domains unique to gokushoviruses. Thus, within one family, different assembly paths have been taken, demonstrating how a two-scaffolding protein system can evolve into a one-scaffolding protein system, or vice versa.
登录
查看更多内容
phiX174 蛋白 J 介导 DNA 包装和病毒与宿主细胞的附着。
影响因子：
5.6
作者：
R. Bernal;S. Hafenstein;R. Esmeralda;B. Fane;M. Rossmann
通讯作者：
M. Rossmann
单链 DNA 噬菌体 phi X174 的分析，分辨率为 3.0 A。
影响因子：
5.6
作者：
Robert McKenna;L. Ilag;Michael G. Rossmann
通讯作者：
Michael G. Rossmann
DOI：
10.1107/s2059798318006551
发表时间：
2018-06-01
期刊：
Acta crystallographica. Section D, Structural biology
影响因子：
--
作者：
Afonine PV;Poon BK;Read RJ;Sobolev OV;Terwilliger TC;Urzhumtsev A;Adams PD
通讯作者：
Adams PD
一致。
DOI：
10.1097/iae.0000000000001602
发表时间：
2017
期刊：
Retina (Philadelphia, Pa.)
影响因子：
--
作者：
Todorich,Bozho;Thanos,Aristomenis;Yonekawa,Yoshihiro;Thomas,BenjaminJ;Faia,LisaJ;Chang,Emmanuel;Shulman,Julia;Olsen,KarlR;Blair,MichaelP;Shapiro,MichaelP;Ferrone,Philip;Vajzovic,Lejla;Toth,CynthiaA;Lee,ThomasC;Robinson,
通讯作者：
Robinson,
影响因子：
3
作者：
Heymann, J. Bernard;Belnap, David M.
通讯作者：
Belnap, David M.