Dekker P J, Papadopoulou B, Grivell L A
Department of Molecular Cell Biology, University of Amsterdam, The Netherlands.
Curr Genet. 1993 Jan;23(1):22-7. doi: 10.1007/BF00336745.
In an attempt to reconstitute an homologous in-vitro translation system for yeast mitochondrial mRNAs, we have isolated ribosomes, supernatant factors, and tRNAs from mitochondria of Saccharomyces carlsbergensis. While poly(U) is translated faithfully in this system, no translation of in-vitro synthesised cytochrome c oxidase subunit II (COX2) mRNA could be detected. Formation of formylmethionyl-puromycin on mitochondrial ribosomes is stimulated by ApUpG, but not by COX2 mRNA, although mitochondrial small ribosomal subunits bind to this mRNA in vitro, even without added tRNA and initiation factors. We conclude, therefore, that the inability to faithfully translate mitochondrial mRNAs in vitro may be the result of an inability of mitochondrial ribosomes to recognize the initiation codon.
为了重建用于酵母线粒体mRNA的同源体外翻译系统，我们从卡尔斯伯酵母的线粒体中分离出核糖体、上清因子和tRNA。虽然聚尿嘧啶（poly(U)）在该系统中能被准确翻译，但未检测到体外合成的细胞色素c氧化酶亚基II（COX2）mRNA的翻译。尽管线粒体小核糖体亚基在体外能与该mRNA结合，甚至无需添加tRNA和起始因子，但ApUpG可刺激线粒体核糖体上甲酰甲硫氨酰嘌呤霉素的形成，而COX2 mRNA则不能。因此，我们得出结论，体外无法准确翻译线粒体mRNA可能是线粒体核糖体无法识别起始密码子的结果。
