Strobel S A
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
Biopolymers. 1998;48(1):65-81. doi: 10.1002/(SICI)1097-0282(1998)48:1<65::AID-BIP7>3.0.CO;2-D.
In this review I will outline several chemogenetic approaches used to determine the chemical basis of large ribozyme function and structure. The term chemogenetics was first used to describe site-specific functional group modification experiments in the analysis of DNA-protein interactions. Within the past few years equivalent experiments have been performed on large catalytic RNAs using both single-site substitution and interference mapping techniques with nucleotide analogues. While functional group mutagenesis is an important aspect of a chemogenetic approach, chemical correlates to genetic revertants and suppressors must also be realized for the genetic analogy to be intellectually valid and experimentally useful. Several examples of functional group revertants and suppressors have now been obtained within the Tetrahymena group I ribozyme. These experiments define an ensemble of tertiary hydrogen bonds that have made it possible to construct a detailed model of the ribozyme catalytic core. The model includes a functionally important monovalent metal ion binding site, a wobble-wobble receptor motif for helix-helix packing interactions, and a minor groove triple helix.
在这篇综述中，我将概述几种用于确定大型核酶功能和结构化学基础的化学遗传学方法。“化学遗传学”一词最初用于描述分析DNA-蛋白质相互作用时的位点特异性官能团修饰实验。在过去几年中，利用核苷酸类似物通过单位点取代和干涉图谱技术，对大型催化RNA进行了等效实验。虽然官能团诱变是化学遗传学方法的一个重要方面，但为了使遗传类比在理论上有效且在实验中有用，还必须认识到与遗传回复突变体和抑制子相关的化学因素。现在，在嗜热四膜虫I组核酶中已经获得了几个官能团回复突变体和抑制子的例子。这些实验确定了一组三级氢键，从而有可能构建核酶催化核心的详细模型。该模型包括一个功能重要的单价金属离子结合位点、一个用于螺旋-螺旋堆积相互作用的摆动-摆动受体基序和一个小沟三螺旋。
