AN ANCIENT GROUP-I INTRON SHARED BY EUBACTERIA AND CHLOROPLASTS
AN ANCIENT GROUP-I INTRON SHARED BY EUBACTERIA AND CHLOROPLASTS
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DOI：
10.1126/science.2125748
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发表时间：
1990-12-14
期刊：
影响因子：
56.9
通讯作者：
PALMER, JD
中科院分区：
文献类型：
--
作者：
KUHSEL, MG;STRICKLAND, R;PALMER, JD
内含子存在于除真细菌外的所有主要生物群体的基因组中。叶绿体和线粒体中内含子的存在，这两者都是真细菌的起源，已被解释为证据，无论是最近收购的内含子的细胞器或内含子的损失，从他们的真细菌的祖先。从五种不同的蓝藻和几个主要的叶绿体群体中获得的带有UAA反密码子的亮氨酸转移RNA [tRNALeu（UAA）]基因含有一个I组内含子。内含子在二级结构和一级序列中是保守的，并且在UAA反密码子内占据相同的位置。内含子在叶绿体和蓝细菌中的同源性意味着它存在于它们的共同祖先中，并且已经在它们的基因组中维持了至少10亿年。
Introns have been found in the genomes of all major groups of organisms except eubacteria. The presence of introns in chloroplasts and mitochondria, both of which are of eubacterial origin, has been interpreted as evidence either for the recent acquisition of introns by organelles or for the loss of introns from their eubacterial progenitors. The gene for the leucine transfer RNA with a UAA anticodon [tRNALeu (UAA)] from five diverse cyanobacteria and several major groups of chloroplasts contains a single group I intron. The intron is conserved in secondary structure and primary sequence, and occupies the same position, within the UAA anticodon. The homology of the intron across chloroplasts and cyanobacteria implies that it was present in their common ancestor and that it has been maintained in their genomes for at least 1 billion years.