Hensgens L A, Bonen L, de Haan M, van der Horst G, Grivell L A
Cell. 1983 Feb;32(2):379-89. doi: 10.1016/0092-8674(83)90457-9.
The DNA sequences of two optional introns in the gene for subunit I of cytochome c oxidase in yeast mitochondrial DNA have been determined. Both contain long unassigned reading frames (URFs). These display regions of amino acid homology with six other URFs, two of which encode proteins involved in mitochondrial RNA splicing. Such conserved regions may thus define functionally important domains of proteins involved in RNA processing. This homology also implies that these URFs had a common ancestral sequence, which has been duplicated and dispersed around the genome. Comparison of the flanking exons in the long strain KL14-4A with their unsplit counterpart in D273-10B reveals clustered sequence differences, which lead in D273-10B to codons rarely used in exons. These differences may be linked to the loss or absence of one of the optional introns.
已确定酵母线粒体DNA中细胞色素c氧化酶亚基I基因中两个可选内含子的DNA序列。两者都包含长的未分配阅读框（URF）。这些URF与其他六个URF显示出氨基酸同源区域，其中两个编码参与线粒体RNA剪接的蛋白质。因此，这种保守区域可能定义了参与RNA加工的蛋白质的功能重要结构域。这种同源性还意味着这些URF有一个共同的祖先序列，该序列已在基因组中复制并分散。将长菌株KL14-4A中的侧翼外显子与其在D273-10B中的未分割对应物进行比较，发现了成簇的序列差异，这导致D273-10B中的外显子中很少使用密码子。这些差异可能与其中一个可选内含子的缺失或不存在有关。
