Energetic cost of building a virus
Energetic cost of building a virus
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DOI：
10.1073/pnas.1701670114
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发表时间：
2017-05-30
影响因子：
11.1
通讯作者：
Phillips, Rob
中科院分区：
文献类型：
--
作者：
Mahmoudabadi, Gita;Milo, Ron;Phillips, Rob
病毒不能自主产生能量。尽管许多实验研究表明病毒是劫持宿主分子资源的寄生实体，但在很大程度上缺乏对病毒合成的能量成本的详细估计。为了量化病毒对其宿主的能量消耗，我们列举了两种非常不同但具有代表性的DNA和RNA病毒（即T4和流感病毒）的能量消耗。我们发现，对于这些病毒，病毒蛋白的翻译是能量最昂贵的过程。有趣的是，构建T4噬菌体和构建单一流感病毒的成本几乎相同。然而，由于流感病毒的爆发规模更大，T4噬菌体感染的总成本仅为流感病毒感染成本的2-3%。这些感染的成本相对于其宿主在感染期间的估计能量预算显示，T4感染消耗其宿主能量预算的约三分之一，而流感感染仅消耗约1%。在我们对T4的估计的基础上，我们展示了双链DNA的能量成本如何随着衣壳大小而变化，揭示了构建病毒的主要成本可以在临界大小以上从翻译切换到基因组复制。最后，使用我们对病毒能量成本的预测，我们提供了在能量限制的条件下，对病毒基因组中新纳入的遗传元件的选择和遗传漂变的强度的估计。
Viruses are incapable of autonomous energy production. Although many experimental studies make it clear that viruses are parasitic entities that hijack the molecular resources of the host, a detailed estimate for the energetic cost of viral synthesis is largely lacking. To quantify the energetic cost of viruses to their hosts, we enumerated the costs associated with two very distinct but representative DNA and RNA viruses, namely, T4 and influenza. We found that, for these viruses, translation of viral proteins is the most energetically expensive process. Interestingly, the costs of building a T4 phage and a single influenza virus are nearly the same. Due to influenza's higher burst size, however, the overall cost of a T4 phage infection is only 2-3% of the cost of an influenza infection. The costs of these infections relative to their host's estimated energy budget during the infection reveal that a T4 infection consumes about a third of its host's energy budget, whereas an influenza infection consumes only approximate to 1%. Building on our estimates for T4, we show how the energetic costs of double-stranded DNA phages scale with the capsid size, revealing that the dominant cost of building a virus can switch from translation to genome replication above a critical size. Last, using our predictions for the energetic cost of viruses, we provide estimates for the strengths of selection and genetic drift acting on newly incorporated genetic elements in viral genomes, under conditions of energy limitation.