Different Trypanosoma brucei guide RNA molecules associate with an identical complement of mitochondrial proteins in vitro.
Different Trypanosoma brucei guide RNA molecules associate with an identical complement of mitochondrial proteins in vitro.
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不同的布氏锥虫引导 RNA 分子在体外与相同的线粒体蛋白互补体相关联。
DOI：
10.1093/nar/22.11.1988
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发表时间：
1994
影响因子：
14.9
通讯作者：
Göringer,HU
中科院分区：
文献类型：
--
作者：
Köller,J;Nörskau,G;Paul,AS;Stuart,K;Göringer,HU
Krna编辑是在动质类原生动物中进化的线粒体转录成熟过程。它需要插入和删除专门由gRNAs定向的尿苷核苷酸到前mRNAs。其他参与的组件目前尚不清楚。这项研究的目的是确定与gRNA直接物理接触的线粒体蛋白，从而可能参与编辑反应。在较低的单价阳离子浓度(30 MM KCI)下，8个表观分子量在124~9 kDa之间的多肽与gRNA发生特异性交联。其中三种蛋白质，90、21和9 kDa，能够在较高的盐浓度(≥100 mM)下结合，表明与gRNA分子的亲和力增强。在≥250mMKCI处未发现交联链。四个针对ATPase 6和ND7前-mRNAs不同编辑域的gRNAs与同一组线粒体多肽接触，表明组装了一个相同的RNP复合体，但不包括前-mRNAs分子。90 kDa蛋白的结合对gRNAs 3‘端的U-核苷酸很敏感，可以通过修饰游离巯基而被特异性地阻断。与124 kDa多肽的相互作用被糖核苷所抑制，提示2‘，3’羟基在gRNA-蛋白质相互作用中起作用。
kRNA editing is a mitochondrial transcript maturation process which evolved in kinetoplastid protozoa. It entails the insertion and deletion of exclusively uridine nucleotides directed by gRNAs into pre-mRNAs. Other participating components are not currently known. The aim of this study was to identify mitochondrial proteins that are in direct physical contact with gRNAs thereby possibly involved in the editing reaction. At low monovalent cation concentration (30 mM KCI) 8 polypeptides with apparent molecular weights ranging from 124 to 9 kDa specifically cross-linked to gRNAs. Three of the proteins, 90, 21, and 9 kDa in size, were able to bind at higher salt concentrations (≥100 mM) indicating an enhanced affinity to the gRNA molecules. No cross-links were identified at ≥250 mM KCI. Four gRNAs, specific for different editing domains of the ATPase 6 and ND7 pre-mRNAs, were in contact with the same set of mitochondrial polypeptides suggesting the assembly of an identical RNP complex that does not include pre-mRNA molecules. The binding of the 90 kDa protein was sensitive to the presence of U-nucleotides at the 3′-end of the gRNAs and could specifically be blocked by modifying free sulfhydryl groups. The interaction with the 124 kDa polypeptide was inhibited by vanadyl ribonucleosides, implicating a role for 2′, 3′ hydroxyl groups in the gRNA-protein interaction.