The reversible condensation and expansion of the rotavirus genome.
The reversible condensation and expansion of the rotavirus genome.
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轮状病毒基因组的可逆缩合和扩展。
DOI：
10.1073/pnas.98.4.1381
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发表时间：
2001
影响因子：
11.1
通讯作者：
VenkataramPrasad,BV
中科院分区：
文献类型：
--
作者：
Pesavento,JB;Lawton,JA;Estes,ME;VenkataramPrasad,BV
了解基因组的结构组织在节段式双链RNA病毒中尤其相关，这种病毒具有内源性转录活性。这些病毒是分子机器，能够在完整的衣壳内重复转录循环。轮状病毒是一种典型的节段性双链RNA病毒，是引起婴幼儿胃肠炎的主要原因。我们用电子冷冻显微镜对轮状病毒在不同化学条件下进行的三维结构分析表明，通过可逆地改变其包装密度，病毒基因组显示出显著的构象灵活性。在高pH的氨离子存在下，基因组从≈220Å凝聚到半径为≈180Å的范围内。一旦回到生理状态，基因组就会重新扩张，并完全保持其转录特性。这些研究提供了对基因组组织的进一步洞察，并表明所观察到的等轴测和同心性质的凝聚是由于基因组核心和锚定在衣壳内表面的转录酶之间的强烈相互作用。基因组的浓缩能力超出了在天然病毒中正常观察到的范围，这表明天然状态下的RNA上的负电荷可能只被部分中和了。在转录过程中，可能需要部分中和来保持适当的链间距，以便模板在酶复合体周围移动。无论是在正常pH下还是在没有氨离子的高pH条件下，都没有观察到随着阳离子浓度的增加而发生基因组缩合。这一发现表明，观察到的基因组缩合是羟基和氨离子的协同效应，涉及蛋白质-RNA相互作用的破坏，这可能有助于进一步的电荷中和，从而减少链间距。
Understanding the structural organization of the genome is particularly relevant in segmented double-stranded RNA viruses, which exhibit endogenous transcription activity. These viruses are molecular machines capable of repeated cycles of transcription within the intact capsid. Rotavirus, a major cause of infantile gastroenteritis, is a prototypical segmented double-stranded RNA virus. From our three-dimensional structural analyses of rotavirus examined under various chemical conditions using electron cryomicroscopy, we show here that the viral genome exhibits a remarkable conformational flexibility by reversibly changing its packaging density. In the presence of ammonium ions at high pH, the genome condenses to a radius of ≈180 Å from ≈220 Å. Upon returning to physiological conditions, the genome re-expands and fully maintains its transcriptional properties. These studies provide further insights into the genome organization and suggest that the observed isometric and concentric nature of the condensation is due to strong interactions between the genome core and the transcription enzymes anchored to the capsid inner surface. The ability of the genome to condense beyond what is normally observed in the native virus indicates that the negative charges on the RNA in the native state may be only partially neutralized. Partial neutralization may be required to maintain appropriate interstrand spacing for templates to move around the enzyme complexes during transcription. Genome condensation was not observed either with increased cation concentrations at normal pH or at high pH without ammonium ions. This finding indicates that the observed genome condensation is a synergistic effect of hydroxyl and ammonium ions involving disruption of protein–RNA interactions that perhaps facilitate further charge neutralization and consequent reduction in the interstrand spacing.
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影响因子：
5.4
作者：
R. Smith;Y. Furuichi
通讯作者：
R. Smith;Y. Furuichi
影响因子：
56.9
作者：
GILLIES, S;BULLIVANT, S;BELLAMY, AR
通讯作者：
BELLAMY, AR
影响因子：
11.4
作者：
Butcher, SJ;Dokland, T;Fuller, SD
通讯作者：
Fuller, SD
通过 400 kV 点扫描电子冷冻显微镜测定单纯疱疹病毒 A 衣壳中的蛋白质亚基结构。
影响因子：
5.6
作者：
Zhou,ZH;Prasad,BV;Jakana,J;Rixon,FJ;Chiu,W
通讯作者：
Chiu,W
用于二十面体病毒重建的自动化软件包。
DOI：
10.1006/jsbi.1996.0032
发表时间：
1996
期刊：
Journal of structural biology.
影响因子：
--
作者：
Lawton,JA;VenkataramPrasad,BV
通讯作者：
VenkataramPrasad,BV