Luban Cornelia, Beutel Melanie, Stahl Ulf, Schmidt Udo
Department of Microbiology and Genetics, Faculty III, University of Technology Berlin, TIB 4/4-1, 13355 Berlin, Gustav-Meyer-Allee 25, Germany.
Gene. 2005 Jul 18;354:72-9. doi: 10.1016/j.gene.2005.03.023.
Studies of yeast, algae and plants have provided genetic and biochemical evidence that the splicing reaction of organellar localized group II introns either depends on proteins encoded by the introns themselves ('maturases') or encoded by other genes of the host organisms. However, only a few of those proteins have been identified to date and characterized in more detail. In order to find new nuclear encoded proteins that assist group II splicing, we screened a complete knockout library of Saccharomyces cerevisiae strain BY4741 consisting of 4878 viable haploid clones. The strain contains a rho+ mitochondrial genome with a set of 13 introns including the three group II introns (aI1, aI2, aI5gamma) in the gene encoding cytochrome-c-oxidase subunit 1 (COX1) and the single group II intron (bI1) in the gene encoding cytochrome b (CYTB). In our screen and initial molecular analysis, we focus on intron aI5gamma, the last intron in the COX1 gene.
对酵母、藻类和植物的研究已提供了遗传和生化证据，表明细胞器定位的II类内含子的剪接反应要么依赖于内含子自身编码的蛋白质（“成熟酶”），要么依赖于宿主生物体其他基因所编码的蛋白质。然而，迄今为止，仅鉴定出少数几种此类蛋白质并对其进行了更详细的表征。为了寻找协助II类剪接的新的核编码蛋白质，我们筛选了酿酒酵母BY4741菌株的一个完整敲除文库，该文库由4878个存活的单倍体克隆组成。该菌株含有一个rho+线粒体基因组，带有一组13个内含子，包括细胞色素c氧化酶亚基1（COX1）编码基因中的三个II类内含子（aI1、aI2、aI5γ）以及细胞色素b（CYTB）编码基因中的单个II类内含子（bI1）。在我们的筛选和初步分子分析中，我们聚焦于COX1基因中的最后一个内含子aI5γ。
