Beaudry A A, Joyce G F
Department of Chemistry, Research Institute of Scripps Clinic, La Jolla, California 92037.
Biochemistry. 1990 Jul 10;29(27):6534-9. doi: 10.1021/bi00479a027.
We have completed a comprehensive deletion analysis of the Tetrahymena ribozyme in order to define the minimum secondary structure requirements for phosphoester transfer activity of a self-splicing group I intron. A total of 299 nucleotides were removed in a piecewise fashion, leaving a catalytic core of 114 nucleotides that form 7 base-paired structural elements. Among the various deletion mutants are a 300-nucleotide single-deletion mutant and a 281-nucleotide double-deletion mutant whose activity exceeds that of the wild type when tested under physiologic conditions. Consideration of those structural elements that are essential for catalytic activity leads to a simplified secondary structure model of the catalytic core of a group I intron.
为了确定自我剪接的I组内含子磷酸酯转移活性的最小二级结构要求，我们已完成对嗜热四膜虫核酶的全面缺失分析。总共以分段方式去除了299个核苷酸，留下了由114个核苷酸组成的催化核心，这些核苷酸形成7个碱基配对的结构元件。在各种缺失突变体中，有一个300个核苷酸的单缺失突变体和一个281个核苷酸的双缺失突变体，在生理条件下测试时其活性超过野生型。对催化活性必不可少的那些结构元件的研究，得出了I组内含子催化核心的简化二级结构模型。
