The Spliceosome and Its Metal Ions
The Spliceosome and Its Metal Ions
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DOI：
10.1039/978184973251200235
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发表时间：
2011-01-01
期刊：
影响因子：
--
通讯作者：
Butcher, Samuel E.
中科院分区：
文献类型：
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作者：
Butcher, Samuel E.
剪接体是一个由5种RNA和许多蛋白质组成的巨大复合体，它们催化前体信使RNA剪接。剪接过程包括两种磷酸化转移反应，导致内含子切除和侧翼外显子的连接。由于它是真核细胞正常蛋白质生产所必需的，前mrna剪接是基因表达的重要步骤。虽然剪接体的高分辨率结构尚不存在，但越来越多的证据表明，剪接体是一种镁依赖性酶，它利用催化金属离子来稳定剪接的两个磷酸化转移步骤中的过渡态。大量的数据还表明，剪接体的核心是由RNA组成的，这表明剪接体可能是一种核酶。本章介绍了剪接体对金属离子催化的证据，并与类似的RNA酶进行了比较，讨论了pre-mRNA剪接机制的未来研究方向。
The spliceosome is a massive complex of 5 RNAs and many proteins that associate to catalyze precursor messenger RNA splicing. The process of splicing involves two phosphoryl transfer reactions that result in intron excision and ligation of the flanking exons. Since it is required for normal protein production in eukaryotic cells, pre-mRNA splicing is an essential step in gene expression. Although high resolution structural views of the spliceosome do not yet exist, a growing body of evidence indicates that the spliceosome is a magnesium-dependent enzyme that utilizes catalytic metal ions to stabilize both transition states during the two phosphoryl transfer steps of splicing. A wealth of data also indicate that the core of the spliceosome is comprised of RNA, and suggest that the spliceosome may be a ribozyme. This chapter presents the evidence for metal ion catalysis by the spliceosome, draws comparisons to similar RNA enzymes, and discusses the future directions for research into the mechanism of pre-mRNA splicing.