Energy-efficient growth of phage Qβ in Escherichia coli
Energy-efficient growth of phage Qβ in Escherichia coli
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DOI：
10.1002/bit.20226
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发表时间：
2004-10-20
影响因子：
3.8
通讯作者：
Yin, J
中科院分区：
文献类型：
--
作者：
Kim, H;Yin, J
自然选择在生物体优化设计中的作用是有争议的。生物体的最佳形式、功能或行为长期以来一直被认为是在不了解基因型如何影响表型、设计约束的描述或替代设计的情况下提出的。此外，最佳设计的论点往往是基于难以（如果不是不可能的话）测试的模型。在这里，我们开始，以解决这些问题，通过开发和探测在大肠杆菌中的噬菌体Q β的细胞内生长的动力学模型。该模型考虑了所有模板依赖性聚合反应的能量成本，以ATP当量计，包括噬菌体复制酶的RNA依赖性RNA延伸和E. coli宿主细胞。我们发现，翻译占主导地位的噬菌体生长，需要85%的总能量消耗。只有10%的总能量被用于除直接合成子代噬菌体组分之外的活动，主要反映了制备噬菌体基因组RNA复制所需的负链RNA模板的成本。此外，我们定义了噬菌体生长的能量效率，并显示其与噬菌体后代产量的直接关系。最后，我们进行了敏感性分析，发现野生型噬菌体的生长是优化的后代产量或能量效率，这表明噬菌体Qbeta已经进化到最佳利用其宿主细胞的有限资源。(C)2004 Wiley Periodicals，Inc.
The role of natural selection in the optimal design of organisms is controversial. Optimal forms, functions, or behaviors of organisms have long been claimed without knowledge of how genotype contributes to phenotype, delineation of design constraints, or reference to alternative designs. Moreover, arguments for optimal designs have been often based on models that were difficult, if not impossible, to test. Here, we begin to address these issues by developing and probing a kinetic model for the intracellular growth of bacteriophage Qbeta in Escherichia coli. The model accounts for the energetic costs of all template-dependent polymerization reactions, in ATP equivalents, including RNA-dependent RNA elongation by the phage replicase and synthesis of all phage proteins by the translation machinery of the E. coli host cell. We found that translation dominated phage growth, requiring 85% of the total energy expenditure. Only 10% of the total energy was applied to activities other than the direct synthesis of progeny phage components, reflecting primarily the cost of making the negative-strand RNA template that is needed for replication of phage genomic RNA. Further, we defined an energy efficiency of phage growth and showed its direct relationship to the yield of phage progeny. Finally, we performed a sensitivity analysis and found that the growth of wild-type phage was optimized for progeny yield or energy efficiency, suggesting that phage Qbeta has evolved to optimally utilize the finite resources of its host cells. (C) 2004 Wiley Periodicals, Inc.