Panigrahi A K, Schnaufer A, Carmean N, Igo R P, Gygi S P, Ernst N L, Palazzo S S, Weston D S, Aebersold R, Salavati R, Stuart K D
Seattle Biomedical Research Institute, Seattle, Washington 98109, USA.
Mol Cell Biol. 2001 Oct;21(20):6833-40. doi: 10.1128/MCB.21.20.6833-6840.2001.
RNA editing in kinetoplastid mitochondria occurs by a series of enzymatic steps that is catalyzed by a macromolecular complex. Four novel proteins and their corresponding genes were identified by mass spectrometric analysis of purified editing complexes from Trypanosoma brucei. These four proteins, TbMP81, TbMP63, TbMP42, and TbMP18, contain conserved sequences to various degrees. All four proteins have sequence similarity in the C terminus; TbMP18 has considerable sequence similarity to the C-terminal region of TbMP42, and TbMP81, TbMP63, and TbMP42 contain zinc finger motif(s). Monoclonal antibodies that are specific for TbMP63 and TbMP42 immunoprecipitate in vitro RNA editing activities. The proteins are present in the immunoprecipitates and sediment at 20S along with the in vitro editing, and RNA editing ligases TbMP52 and TbMP48. Recombinant TbMP63 and TbMP52 coimmunoprecipitate. These results indicate that these four proteins are components of the RNA editing complex and that TbMP63 and TbMP52 can interact.
动质体线粒体中的RNA编辑通过一系列由大分子复合物催化的酶促步骤进行。通过对来自布氏锥虫的纯化编辑复合物进行质谱分析，鉴定出了四种新蛋白质及其相应基因。这四种蛋白质，即TbMP81、TbMP63、TbMP42和TbMP18，在不同程度上含有保守序列。所有四种蛋白质在C末端都有序列相似性；TbMP18与TbMP42的C末端区域有相当大的序列相似性，并且TbMP81、TbMP63和TbMP42含有锌指基序。对TbMP63和TbMP42具有特异性的单克隆抗体在体外免疫沉淀RNA编辑活性。这些蛋白质存在于免疫沉淀物中，并与体外编辑以及RNA编辑连接酶TbMP52和TbMP48一起在20S处沉降。重组TbMP63和TbMP52共免疫沉淀。这些结果表明这四种蛋白质是RNA编辑复合物的组成部分，并且TbMP63和TbMP52可以相互作用。
