Covello P S, Gray M W
Canadian Institute for Advanced Research, Department of Biochemistry, Dalhousie University, Halifax, Nova Scotia.
EMBO J. 1992 Nov;11(11):3815-20. doi: 10.1002/j.1460-2075.1992.tb05473.x.
In most plants and other eukaryotes investigated, the mitochondrial genome carries the gene encoding subunit 2 of cytochrome c oxidase (cox2). In this paper, we show that the previously reported mitochondrial cox2 of soybean is actually silent, and that there is an expressed, single-copy, nucleus-encoded cox2. Molecular cloning and sequence analysis of cox2 cDNA and genomic clones show that the soybean nuclear gene encodes an N-terminal extension that resembles a signal sequence for mitochondrial import and whose coding sequence is separated by an intron from that corresponding to mtDNA-encoded cox2. Comparison of soybean mitochondrial and nuclear cox2 sequences clearly indicates that in an ancestor of soybean, cox2 was transferred from the mitochondrion to the nucleus via a C-to-U edited RNA intermediate.
在大多数已研究的植物和其他真核生物中，线粒体基因组携带着编码细胞色素c氧化酶亚基2（cox2）的基因。在本文中，我们表明，先前报道的大豆线粒体cox2实际上是沉默的，并且存在一个表达的、单拷贝的、核编码的cox2。cox2 cDNA和基因组克隆的分子克隆及序列分析表明，大豆核基因编码一个N端延伸序列，该序列类似于线粒体导入的信号序列，其编码序列与线粒体DNA编码的cox2的对应序列被一个内含子隔开。大豆线粒体和核cox2序列的比较清楚地表明，在大豆的一个祖先中，cox2通过C到U编辑的RNA中间体从线粒体转移到了细胞核。
