Morawala-Patell V, Gualberto J M, Lamattina L, Grienenberger J M, Bonnard G
Institut de Biologie Moléculaire des Plantes du CNRS, Université Louis Pasteur, Strasbourg, France.
Mol Gen Genet. 1998 Jun;258(5):503-11. doi: 10.1007/s004380050761.
In wheat mitochondria, the gene coding for subunit 2 of the NADH-ubiquinone oxidoreductase (nad2) is divided into five exons located in two distant genomic regions. The first two exons of the gene, a and b, lie 22 kb downstream of exons c, d, and e, on the same DNA strand. All introns of nad2 are group II introns. A trans-splicing event is required to join exons b and c. It involves base pairing of the two precursor RNAs in the stem of domain IV of the intron. A gene coding for tRNA(Tyr) is located upstream of exon c. In addition to splicing processes, mRNA editing is also required for the correct expression of nad2. The mature mRNA is edited at 36 positions, distributed over its five exons, resulting in 28 codon modifications. Editing increases protein hydrophobicity and conservation.
在小麦线粒体中，编码NADH-泛醌氧化还原酶亚基2（nad2）的基因被分为五个外显子，位于两个遥远的基因组区域。该基因的前两个外显子a和b，位于外显子c、d和e下游22 kb处，在同一条DNA链上。nad2的所有内含子均为II类内含子。需要一个反式剪接事件来连接外显子b和c。它涉及内含子结构域IV茎中两个前体RNA的碱基配对。一个编码tRNA（Tyr）的基因位于外显子c的上游。除了剪接过程外，nad2的正确表达还需要mRNA编辑。成熟的mRNA在36个位置被编辑，分布在其五个外显子上，导致28个密码子修饰。编辑增加了蛋白质的疏水性和保守性。
