THE NCS3 MUTATION - GENETIC-EVIDENCE FOR THE EXPRESSION OF RIBOSOMAL-PROTEIN GENES IN ZEA-MAYS MITOCHONDRIA
THE NCS3 MUTATION - GENETIC-EVIDENCE FOR THE EXPRESSION OF RIBOSOMAL-PROTEIN GENES IN ZEA-MAYS MITOCHONDRIA
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DOI：
10.1002/j.1460-2075.1991.tb08043.x
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发表时间：
1991-05-01
期刊：
影响因子：
11.4
通讯作者：
NEWTON, KJ
中科院分区：
文献类型：
--
作者：
HUNT, MD;NEWTON, KJ
在玉米非染色体条纹3（NCS3）突变体中发现了线粒体DNA（mtDNA）转录区的一部分缺失。这导致一组三种线粒体RNA的特异性丢失，在正常植物中，这组三种线粒体RNA由4.9kb转录物、其1.8kb内含子和所得的约2.9kb的加工mRNA组成。 在NCS3线粒体基因组中，编码推定启动子和受影响RNA的5'端的DNA缺失。 正常玉米线粒体DNA的转录区已被测序，内含子剪接点已被确定。 2.9 kb的加工mRNA携带两个重叠的开放阅读框（ORF），其预测的氨基酸序列显示出与两种大肠杆菌核糖体蛋白S3（rps3）和L16（rpl16）的相似性。 NCS3植物中严重发育迟缓和条纹的存在与这里描述的分子变化绝对相关。 这一事实和NCS3植物线粒体蛋白质合成能力受损表明，这些阅读框中的一个或两个在正常玉米线粒体中被翻译成功能性核糖体蛋白。
A deletion eliminating part of a transcribed region of mitochondrial DNA (mtDNA) has been found in the maize nonchromosomal stripe 3 (NCS3) mutant. This results in the specific loss of a set of three mitochondrial RNAs consisting, in normal plants, of a 4.9 kb transcript, its 1.8 kb intron and the resulting processed mRNA of approximately 2.9 kb. In the NCS3 mitochondrial genome the DNA encoding the putative promoter and 5' end of the affected RNAs is missing. This transcribed region of normal maize mtDNA has been sequenced and the intron splice junction has been determined. The 2.9 kb processed mRNA carries two overlapping open reading frames (ORFs) with predicted amino acid sequences that show similarity to two Escherichia coli ribosomal proteins, S3 (rps3) and L16 (rpl16). The presence of severe stunting and striping in NCS3 plants correlated absolutely with the molecular changes described here. This fact and the impaired ability for mitochondrial protein synthesis by NCS3 plants indicate that one or both of these reading frames are translated to functional ribosomal proteins in normal maize mitochondria.