Hoch B, Maier R M, Appel K, Igloi G L, Kössel H
Institut für Biologie III, Universität Freiburg, Germany.
Nature. 1991 Sep 12;353(6340):178-80. doi: 10.1038/353178a0.
Primary mRNA transcripts in several systems are edited by single base substitutions, small deletions or insertions to yield functional messenger RNA species. Mitochondrial mRNAs in particular, including those from plants, seem to be the subject of extensive editing, unlike mRNAs encoded by chloroplast DNA, for which the prediction of amino-acid sequence from the corresponding gene sequence is generally unambiguous. Occasionally, however, an ACG codon appears at the 5' terminus of chloroplast genes, where the initiation codon ATG would be expected. Here we present evidence for a C----U editing that is responsible for the conversion of the ACG codon to an AUG initiation codon in the mRNA transcript from the rpl2 gene of the maize plastome, showing that mRNA editing can also occur in chloroplasts.
在多个系统中，初级mRNA转录本会通过单碱基替换、小片段缺失或插入进行编辑，以产生功能性信使RNA种类。特别是线粒体mRNA，包括来自植物的线粒体mRNA，似乎是广泛编辑的对象，这与叶绿体DNA编码的mRNA不同，对于叶绿体DNA编码的mRNA，从相应基因序列预测氨基酸序列通常是明确无误的。然而，偶尔会在叶绿体基因的5'末端出现ACG密码子，而预期的起始密码子是ATG。在这里，我们提供了证据，证明存在一种C→U编辑，它负责将玉米质体基因组rpl2基因的mRNA转录本中的ACG密码子转换为AUG起始密码子，这表明mRNA编辑也可以发生在叶绿体中。
