DIRECTED EVOLUTION OF AN RNA ENZYME
DIRECTED EVOLUTION OF AN RNA ENZYME
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DOI：
10.1126/science.1496376
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发表时间：
1992-07-31
期刊：
影响因子：
56.9
通讯作者：
JOYCE, GF
中科院分区：
文献类型：
--
作者：
BEAUDRY, AA;JOYCE, GF
体外进化过程被用来获得具有特定催化功能的RNA酶。四氢核酶是一类核酶，通过磷酸酯转移机制催化RNA的序列特异性切割，产生了10（13）个四氢核酶的变体群体。这种酶在高温或高MgCl2浓度或两者兼而有之的条件下切割DNA的能力有限。对核酶变异种群施加了选择约束，这样只有那些在生理条件下进行DNA切割的个体才能扩增产生“后代”核酶。在扩增过程中引入突变以保持群体的异质性。这一过程连续重复十代，结果DNA切割活性增强（100倍）。
An in vitro evolution procedure was used to obtain RNA enzymes with a particular catalytic function. A population of 10(13) variants of the, Tetrahynena ribozyme, a group I ribozyme that catalyzes sequence-specific cleavage of RNA via a phosphoester transfer mechanism, was generated. This enzyme has a limited ability to cleave DNA under conditions of high temperature or high MgCl2 concentration, or both. A selection constraint was imposed on the population of ribozyme variants such that only those individuals that carried out DNA cleavage under physiologic conditions were amplified to produce "progeny" ribozymes. Mutations were introduced during amplification to maintain heterogeneity in the population. This process was repeated for ten successive generations, resulting in enhanced (100 times) DNA cleavage activity.