Lamond A I
European Molecular Biology Laboratory, Heidelberg, Germany.
Bioessays. 1993 Sep;15(9):595-603. doi: 10.1002/bies.950150905.
The spliceosome is a large RNA-protein complex that catalyses the removal of introns from nuclear pre-mRNA. A wide range of biochemical and genetical studies shows that the spliceosome comprises three major RNA-protein subunits, the U1, U2 and [U4/U6.U5] small nuclear ribonucleoprotein particles (snRNPs), and an additional group of non-snRNP protein splicing factors. Rapid progress is being made in unravelling the interactions which take place between these factors during the splicing reaction. The emerging picture of the spliceosome reveals a highly dynamic structure that assembles on pre-mRNA transcripts in a stepwise pathway and is organised, at least in part, by complex RNA base-pairing interactions between the small nuclear RNAs (snRNAs) and the intron substrate. Many of these interactions can be detected both in mammalian and yeast spliceosomes, suggesting that the basic splicing mechanism is an ancient one that has been highly conserved during evolution.
剪接体是一种大型核糖核蛋白复合体，负责催化从核内前体信使核糖核酸（pre-mRNA）中去除内含子。大量的生化和遗传学研究表明，剪接体由三个主要的核糖核蛋白亚基组成，即U1、U2和[U4/U6·U5]小核核糖核蛋白颗粒（snRNP），以及另一组非snRNP蛋白剪接因子。在阐明这些因子在剪接反应过程中发生的相互作用方面正在取得迅速进展。剪接体呈现出的新图景揭示了一种高度动态的结构，它以逐步的方式组装在前体信使核糖核酸转录本上，并且至少部分地由小核RNA（snRNA）与内含子底物之间复杂的RNA碱基配对相互作用所组织。其中许多相互作用在哺乳动物和酵母剪接体中都能被检测到，这表明基本的剪接机制是一种古老的机制，在进化过程中得到了高度保守。
