Vaïtilingom M, Stupar M, Grienenberger J M, Gualberto J M
Institut de Biologie Moléculaire des Plantes du CNRS, Université Louis Pasteur, Strasbourg, France.
Mol Gen Genet. 1998 Jun;258(5):530-7. doi: 10.1007/s004380050764.
A gene coding for a protein that shows homologies to prokaryotic ribosomal protein S2 is present in the mitochondrial (mt) genome of wheat (Triticum aestivum). The wheat gene is transcribed as a single mRNA which is edited by C-to-U conversions at seven positions, all resulting in alteration of the encoded amino acid. Homologous gene sequences are also present in the mt genomes of rice and maize, but we failed to identify the corresponding sequences in the mtDNA of all dicotyledonous species tested; in these species the mitochondrial RPS2 is probably encoded in the nucleus. The protein sequence deduced from the wheat rps2 gene sequence has a long C-terminal extension when compared to other prokaryotic RPS2 sequences. This extension presents no similarity with any known sequence and is not conserved in the maize or rice mitochondrial rps2 gene. Most probably, after translation, this peptide extension is processed by a specific peptidase to give rise to the mature wheat mitochondrial RPS2.
在小麦（普通小麦）的线粒体（mt）基因组中存在一个编码与原核核糖体蛋白S2具有同源性的蛋白质的基因。小麦基因转录为单一的mRNA，该mRNA在七个位置通过C到U的转换进行编辑，所有这些编辑均导致编码氨基酸的改变。水稻和玉米的mt基因组中也存在同源基因序列，但我们未能在所有测试的双子叶植物物种的mtDNA中鉴定出相应序列；在这些物种中，线粒体RPS2可能由细胞核编码。与其他原核RPS2序列相比，从小麦rps2基因序列推导的蛋白质序列具有长的C末端延伸。该延伸与任何已知序列均无相似性，并且在玉米或水稻线粒体rps2基因中不保守。很可能在翻译后，该肽延伸由特定的肽酶加工以产生成熟的小麦线粒体RPS2。
