In Vivo Experimental Evolution: Re-evolving RNase P RNA

9981394Dorit该项目提出重新进化所有活细胞代谢机制的关键组成部分，核糖核蛋白RNaseP。 实验进化系统允许替换在E.大肠杆菌细菌与其他工程改造版本。 这些合成版本，来自相关细菌中存在的RNaseP变体，或在实验室中设计的，被置于质粒载体上并用于置换内源性RNaseP。 重复几代的体内实验选择的结果在进化的功能完全的替代品，然后可以比较和对比，他们的自然发生的counters.This研究是第一个明确的尝试，以揭示存在的替代功能版本的重要代谢成分，在自然界中看不到。 虽然当代生物体中存在的RNaseP版本是数十亿年自然进化的精致结果，但它们可能只是细菌面临的催化挑战的一小部分可能解决方案。 该系统深入研究了这些未被采用的道路，并探索了将现有解决方案与给定催化挑战分开的空间。 这样，偶然性、机会和选择所起的相对作用就可以理解了。 该系统还提供了一种通用工具，用于探测代谢机制任何组分的功能灵活性，以及用于测试天然存在的蛋白质和核酸的工程替代物的性能的方法。

9981394DoritThis project proposes to re-evolve a critical component of the metabolic machinery of all living cells, the ribonucleoprotein RNaseP. The experimental evolution system that permits replacement of the naturally occurring RNaseP found in the E. coli bacterium with alternate, engineered versions. These synthetic versions, derived either from the variants of RNaseP present in related bacteria, or designed in the laboratory, are placed on a plasmid vector and used to displace the endogenous RNaseP. Repeated generations of in vivo experimental selection result in the evolution of fully functional alternatives that can then be compared and contrasted to their naturally occurring counterparts.This study is one of the first explicit attempts to uncover the existence of alternate functional versions of important metabolic components that are not seen in the natural world. While the versions of RNaseP present in contemporary organism are the exquisite result of billions of years of natural evolution, they likely represent but a small subset of possible solutions to the catalytic challenges facing bacteria. This system delves into these roads not taken, and explores the space separating existing solutions to a given catalytic challenge. In so doing, the relative roles played by contingency, chance, and selection can be understood. This system also provides a general tool with which to probe the functional flexibility of any component of the metabolic machinery, as well as a method for testing the performance of engineered alternatives to naturally occurring proteins and nucleic acids.H:\popbio\abstracts\fy2000\9981394 (Dorit abstract)