Elimination of Canonical Amino Acid from Escherichia coli by Experimental Evolution

通过实验进化消除大肠杆菌中的经典氨基酸

• 批准号: 0128901
• 负责人: Valerie de Crecy-Lagard
• 金额: $ 31万
• 依托单位: The Scripps Research Institute
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2004-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0128901&HistoricalAwards=false
• 关键词: Elimination; Canonical; Amino; Acid; Escherichia

In all the theories of the evolution of the genetic code, the number of amino acids is hypothesized to have gradually increased from a few to the twenty that now constitute the building-blocks of proteins in living cells. The objective of this research is to recreate a possible evolutionary intermediate in which a living organism contains 19 and not 20 amino acids. This objective would give insight into how protein structures adapt to mutation and open possibilities in terms of designing and selecting organisms adapted to a different chemical composition. Based on encouraging results from recent experiments, this objective will be accomplished by placing a population under selective pressure for the loss of a given amino acid. Two different strategies have been designed to replace isoleucine by valine and threonine by serine in Escherichia coli. These strategies combine selection strategies that exploit classical strain constructions with the use of a continuous culture apparatus that allows long-term experiments.

在所有关于遗传密码进化的理论中，都假设氨基酸的数量从几个逐渐增加到现在构成活细胞中蛋白质的20个。这项研究的目的是重建一个可能的进化中间体，其中活的有机体含有19个而不是20个氨基酸。这一目标将深入了解蛋白质结构如何适应突变，并在设计和选择适应不同化学组成的生物体方面提供可能性。 根据最近实验的令人鼓舞的结果，这一目标将通过将一个群体置于选择压力下以损失给定的氨基酸来实现。已经设计了两种不同的策略来在大肠杆菌中用缬氨酸取代异亮氨酸和用丝氨酸取代苏氨酸。这些策略将利用经典菌株构建的联合收割机选择策略与允许长期实验的连续培养装置的使用相结合。