Palazzo Setareh S, Panigrahi Aswini K, Igo Robert P, Salavati Reza, Stuart Kenneth
Seattle Biomedical Research Institute, 4 Nickerson St., Seattle, WA 98109, USA.
Mol Biochem Parasitol. 2003 Apr 3;127(2):161-7. doi: 10.1016/s0166-6851(02)00333-x.
RNA editing processes kinetoplastid mitochondrial transcripts post-transcriptionally by inserting and deleting uridylates (Us) to produce functional mRNAs. The activities of the RNA ligases in the multienzyme complex (the editosome) that catalyzes editing and of the recombinant proteins were characterized and found to be similar. Ligation of two RNA fragments was enhanced when bridged by a complementary RNA or DNA, which left no gaps or overhangs. An acceptor nucleotide preference of G>U>C>A was observed in the absence of exogenous ATP but U was preferred upon addition of ATP and ligase activity was increased. The substrate specificity and catalytic characteristics indicate that RNA ligase activity contributes to the accuracy of RNA editing.
RNA编辑通过插入和删除尿苷酸（U）对动质体线粒体转录本进行转录后加工，以产生功能性mRNA。对催化编辑的多酶复合物（编辑体）中的RNA连接酶以及重组蛋白的活性进行了表征，发现它们相似。当由互补RNA或DNA桥接时，两个RNA片段的连接会增强，且不留间隙或突出端。在没有外源ATP的情况下，观察到受体核苷酸偏好为G>U>C>A，但添加ATP后U更受青睐，且连接酶活性增加。底物特异性和催化特性表明RNA连接酶活性有助于RNA编辑的准确性。
