Insertional editing of mitochondrial tRNAs of Physarum polycephalum and Didymium nigripes
Insertional editing of mitochondrial tRNAs of Physarum polycephalum and Didymium nigripes
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DOI：
10.1128/mcb.18.12.7521
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发表时间：
1998-12-01
影响因子：
5.3
通讯作者：
Miller, D
中科院分区：
文献类型：
--
作者：
Antes, T;Costandy, H;Miller, D
在多头绒泡菌和黑质钕的线粒体DNA上编码的trna需要插入编辑才能成熟。编辑包括相对于编码tRNA的线粒体DNA序列特异性插入单个胞苷或尿苷，编辑位点位于9个tRNA中的14个不同位置。胞苷插入位点可以位于tRNA三叶草的四个茎中的任何一个，通常形成一个G。C碱基对。在Didymium的tRNA（Lys）和Physarum的tRNA（Glu）的T环中发现了尿苷插入。在这两种trna中，插入产生GUUC序列，该序列在大多数trna中转化为GT Psi C （Psi =伪尿嘧啶）。这种类型的tRNA编辑不同于其他先前描述的tRNA编辑类型，类似于绒泡菌和Didymium中的mRNA和rRNA编辑。绒泡菌和Didymium中类似的tRNA在不同的位置有编辑位点，这表明自绒泡菌和Didymium分化以来，编辑位点已经丢失、获得或两者都有。尽管来自单个tRNA的cdna通常被完全编辑，但来自未加工的多顺反电子tRNA前体的cdna通常缺乏一些编辑位点插入。未加工tRNA中部分编辑序列的富集可能表明tRNA加工需要编辑，或者至少RNA编辑作为tRNA合成的早期事件发生。
tRNAs encoded on the mitochondrial DNA of Physarum polycephalum and Didymium nigripes require insertional editing for their maturation. Editing consists of the specific insertion of a single cytidine or uridine relative to the mitochondrial DNA sequence encoding the tRNA, Editing sites are at 14 different locations in nine tRNAs. Cytidine insertion sites can be located in any of the four stems of the tRNA cloverleaf and usually create a G . C base pair. Uridine insertions have been identified in the T loop of tRNA(Lys) from Didymium and tRNA(Glu) from Physarum. In both tRNAs, the insertion creates the GUUC sequence, which is converted to GT Psi C (Psi = pseudouridine) in most tRNAs. This type of tRNA editing is different from other, previously described types of tRNA editing and resembles the mRNA and rRNA editing in Physarum and Didymium. Analogous tRNAs in Physarum and Didymium have editing sites at different locations, indicating that editing sites have been lost, gained, or both since the divergence of Physarum and Didymium, Although cDNAs derived from single tRNAs are generally fully edited, cDNAs derived from unprocessed polycistronic tRNA precursors often lack some of the editing site insertions. This enrichment of partially edited sequences in unprocessed tRNAs may indicate that editing is required for tRNA processing or at least that RNA editing occurs as an early event in tRNA synthesis.