Assembly and disassembly intermediates of maize streak geminivirus
Assembly and disassembly intermediates of maize streak geminivirus
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DOI：
10.1016/j.virol.2018.09.011
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发表时间：
2018-12-01
期刊：
影响因子：
3.7
通讯作者：
Agbandje-McKenna, Mavis
中科院分区：
文献类型：
--
作者：
Bennett, Antonette;Rodriguez, David;Agbandje-McKenna, Mavis
玉米条纹病毒(MSV)属于双生病毒科。从感染的植物中分离到四种形式的MSV外壳蛋白(CP)组合：双冠状衣壳、T=1二十面体衣壳、CPS五聚体和十聚体。双生衣壳在pH从4.8到7.2的顺序暴露被用来监测衣壳的解体。衣壳在pH为4.8时保持完整，在pH为6.4时解离为十聚体和五聚体，在pH为7.2时聚集。同样，高盐和二价阳离子会导致分解。在低pH和低盐条件下，解离过程被逆转，但导致空的(没有DNA)单一的和成对的衣壳组装。这可能是由于在酸性条件下CP-DNA相互作用的中断，并表明了一种衣壳组装的机制，即基因组被包装成预先形成的空衣壳。这项研究中建立的pH测定提供了一种方法来表征双生病毒组装和拆卸的决定因素。
Maize streak virus (MSV) belongs to the Geminiviridae. Four forms of MSV coat protein (CP) assemblages were isolated from infected plants: geminate capsids, T = 1 icosahedral capsids, pentamers and decamers of CPs. Sequential exposure of geminate capsids to increasing pH, from 4.8 to 7.2 was used to monitor capsid disassembly. The capsids remain intact at pH4.8, disassemble to decamers and pentamers by pH6.4 and aggregate by pH7.2. Similarly, high salt and divalent cations cause disassembly. The disassembly process was reversed in low pH and low salt, but resulted in empty (no DNA) single and geminate capsid assemblies. This is likely due to disruption of CP-DNA interactions under acidic conditions and suggests a mechanism of capsid assembly in which the genome is packaged into preformed empty capsids. The pH assay developed in this study provides a method for characterizing the conditions that are the determinants of geminivirus assembly and disassembly.