Séraphin B, Simon M, Boulet A, Faye G
Institut Curie-Biologie, Orsay, France.
Nature. 1989 Jan 5;337(6202):84-7. doi: 10.1038/337084a0.
Proteins involved in mitochondrial splicing but encoded by nuclear genes have been characterized in Saccharomyces and Neurospora. The role in splicing of these proteins is largely unknown. Here we report that mutations in the nuclear gene MSS116 directly affect the splicing of several introns of the cytochrome b (cob) and cytochrome c oxidase subunit I (cox1) primary transcripts. This implies that the MSS116 protein (pMSS116) is an important component of the mitochondrial splicing machinery. The sequence of the cloned MSS116 gene shows that its protein product is homologous to the translation eIF-4A factor and the human nuclear protein p68. We show further that these proteins share several conserved amino-acid blocks with DNA helicases and related proteins. This suggests that pMSS116 has an RNA helicase activity. RNA helicases may be involved in many different processes including translation and splicing.
参与线粒体剪接但由核基因编码的蛋白质已在酿酒酵母和粗糙脉孢菌中得到鉴定。这些蛋白质在剪接中的作用很大程度上尚不清楚。在此我们报告，核基因MSS116中的突变直接影响细胞色素b（cob）和细胞色素c氧化酶亚基I（cox1）初级转录本中几个内含子的剪接。这意味着MSS116蛋白（pMSS116）是线粒体剪接机制的一个重要组成部分。克隆的MSS116基因序列表明，其蛋白质产物与翻译起始因子eIF - 4A以及人类核蛋白p68同源。我们进一步表明，这些蛋白质与DNA解旋酶及相关蛋白质共享几个保守的氨基酸区域。这表明pMSS116具有RNA解旋酶活性。RNA解旋酶可能参与包括翻译和剪接在内的许多不同过程。
