Direct visualization of uridylate deletion in vitro suggests a mechanism for kinetoplastid RNA editing
Direct visualization of uridylate deletion in vitro suggests a mechanism for kinetoplastid RNA editing
复制标题
DOI：
10.1016/s0092-8674(00)81062-4
复制
发表时间：
1996-03-22
期刊：
影响因子：
64.5
通讯作者：
Stuart, K
中科院分区：
文献类型：
--
作者：
Seiwert, SD;Heidmann, S;Stuart, K
通过将放射性标记的底物RNA和合成的gRNA在T.布鲁氏菌线粒体裂解物。底物RNA切割是gRNA定向的，发生在待缺失的尿苷酸的3'端。U残基似乎在两个前体mRNA半体的再连接之前从5'切割产物的3'末端顺序除去。还产生gRNA/mRNA嵌合分子。时程实验表明，嵌合体出现后裂解中间体和编辑的产品。此外，突变体gRNA促进编辑产物的形成，但不是可检测的嵌合体。我们的研究结果提出了一个模型动质体RNA编辑嵌合分子是非生产性的最终产品的编辑，而不是中间体，作为一个仓库删除U的。
Deletion of uridylates from the 3'-most editing site of synthetic ATPase 6 pre-mRNA can be visualized directly by coincubation of a radiolabeled substrate RNA and a synthetic gRNA in 20S fractions of T. brucei mitochondrial lysates. Substrate RNA cleavage is gRNA directed and occurs 3' to the uridylates to be deleted. U residues appear to be sequentially removed from the 3' end of the 5' cleavage product prior to religation of the two pre-mRNA halves. gRNA/mRNA chimeric molecules are also produced. Time course experiments indicate that chimeras appear after cleavage intermediates and edited product. Furthermore, a mutant gRNA promotes formation of edited product but not detectable chimeras. Our results suggest a model for kinetoplastid RNA editing in which chimeric molecules are nonproductive end products of editing and not intermediates that serve as a repository for deleted U's.