Chemistry and Biology of Self-Cleaving Ribozymes.
Chemistry and Biology of Self-Cleaving Ribozymes.
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DOI：
10.1016/j.tibs.2015.09.001
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发表时间：
2015-11
影响因子：
13.8
通讯作者：
Lupták A
中科院分区：
文献类型：
--
作者：
Jimenez RM;Polanco JA;Lupták A
自切割核酶在30年前就被发现了，但它们的生物分布和催化机制才刚刚开始被确定。每个核酶家族由具有独特活性位点的独特结构定义，所述独特活性位点加速跨家族的相同酯交换反应。生物化学研究表明，一般的酸碱催化是最常见的自裂解机制，但金属离子和代谢产物可以作为辅因子。核酶在自然界中从类病毒到脊椎动物的高度多样化的基因组背景中被发现。它们的生物学作用包括RNA基因组滚环复制过程中的自我切割、反转录转座子的共转录加工以及细菌中代谢物依赖的基因表达调控。其他例子，包括高度保守的哺乳动物核酶，表明许多新的生物学作用尚未被发现。
Self-cleaving ribozymes were discovered thirty years ago, but their biological distribution and catalytic mechanisms are only beginning to be defined. Each ribozyme family is defined by a distinct structure with unique active sites accelerating the same transesterification reaction across the families. Biochemical studies show that general acid-base catalysis is the most common mechanism of self-cleavage, but metal ions and metabolites can be employed as cofactors. Ribozymes have been discovered in highly diverse genomic contexts throughout nature, from viroids to vertebrates. Their biological roles include self-scission during rolling-circle replication of RNA genomes, co-transcriptional processing of retrotransposons, and metabolite-dependent gene expression regulation in bacteria. Other examples, including highly conserved mammalian ribozymes, suggest that many new biological roles are yet to be discovered.