Chapdelaine Y, Bonen L
Department of Biology, University of Ottawa, Canada.
Cell. 1991 May 3;65(3):465-72. doi: 10.1016/0092-8674(91)90464-a.
The nad1 gene encoding subunit I of the respiratory chain NADH dehydrogenase is fragmented into five unique-copy coding segments that are scattered over at least 40 kb and interspersed with other genes in the wheat mitochondrial genome. The nad1 segments are flanked by sequences with group II intron features, and transcript analysis demonstrates the presence of correctly spliced mRNAs. RNA editing occurs at sites asymmetrically distributed along the wheat nad1 coding region, and the initiation codon is created by RNA editing. The unusual organization of the wheat nad1 gene is attributed to mitochondrial DNA rearrangements within introns, and a trans-splicing model involving secondary structural interactions between group II-like intron pieces is proposed for its expression.
编码呼吸链NADH脱氢酶亚基I的nad1基因被分割成五个单拷贝编码片段，这些片段散布在至少40 kb的区域内，并穿插于小麦线粒体基因组中的其他基因之间。nad1片段两侧是具有II类内含子特征的序列，转录本分析表明存在正确剪接的mRNA。RNA编辑发生在沿小麦nad1编码区不对称分布的位点，起始密码子由RNA编辑产生。小麦nad1基因的这种不寻常组织方式归因于内含子内的线粒体DNA重排，并提出了一种涉及II类内含子片段间二级结构相互作用的反式剪接模型来解释其表达。
