Processing of mammalian tRNA transcripts in vitro: different pre-tRNAs are processed along alternative pathways that contain a common rate-limiting step.
Processing of mammalian tRNA transcripts in vitro: different pre-tRNAs are processed along alternative pathways that contain a common rate-limiting step.
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哺乳动物 tRNA 转录本的体外加工：不同的前 tRNA 沿着包含共同限速步骤的替代途径进行加工。
DOI：
10.1093/nar/14.12.4849
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发表时间：
1986
影响因子：
14.9
通讯作者：
Harding,JD
中科院分区：
文献类型：
--
作者：
Rooney,RJ;Harding,JD
我们分析了小鼠tRNA基因体外转录加工的途径和动力学。不同的转录物沿沿着两条可选途径加工。在5′前导序列之前切除tRNAHis初级转录物的3′尾部序列。与此相反，对于tRNAGly初级转录物，5′前导序列在3′尾部序列之前被切除，这在其他单体真核生物tRNA基因转录物中已经发现。加工动力学的计算机分析表明，tRNAAsp、tRNAGly、tRNAGlu和tRNAHi转录物以底物浓度依赖的方式被加工，并且还揭示了共同限速步骤的存在，其速率常数对于所测试的四种转录物中的三种是相等的。一种前体tRNA转录物的加工可以通过向加工反应中加入另一种前体tRNA转录物来竞争性抑制。共同限速步骤与初级转录物向中间体的转化相关，并且与转录物的序列和特定加工途径无关。
We have analyzed the pathways and kinetics of processing of mouse tRNA gene transcriptsin vitro. Different transcripts are processed along two alternative pathways. The 3′ trailer sequence of the tRNAHisprimary transcript is excised before the 5′ leader sequence. In contrast, for the tRNAGlyprimary transcript, the 5′ leader sequence is excised before the 3′ trailer sequence, as has been found for other monomeric eukaryotic tRNA gene transcripts.Computerized analysis of the kinetics of processing indicates that tRNAAsp, tRNAGly, tRNAGluand tRNAHistranscripts are processed in a substrate concentration-dependent manner and also reveals the existence of a common rate-limiting step, the rate constant of which is equivalent for three of the four transcripts tested. The processing of one pre-tRNA transcript can be competitively inhibited by addition of another pre-tRNA transcript to the processing reaction. The common rate-limiting step is associated with the conversion of the primary transcript to an intermediate and is independent of sequence and the particular processing pathway of the transcript.