Turner R J, Lovato M, Schimmel P
Skaggs Institute for Chemical Biology and Departments of Molecular Biology and Chemistry, The Scripps Research Institute, La Jolla, California 92037, USA.
J Biol Chem. 2000 Sep 8;275(36):27681-8. doi: 10.1074/jbc.M003416200.
In the yeast Saccharomyces cerevisiae, two genes (GRS1 and GRS2) encode glycyl-tRNA synthetase (GlyRS1 and GlyRS2, respectively). 59% of the sequence of GlyRS2 is identical to that of GlyRS1. Others have proposed that GRS1 and GRS2 encode the cytoplasmic and mitochondrial enzymes, respectively. In this work, we show that GRS1 encodes both functions, whereas GRS2 is dispensable. In addition, both cytoplasmic and mitochondrial phenotypes of the knockout allele of GRS1 in S. cerevisiae are complemented by the expression of the only known gene for glycyl-tRNA synthetase in Schizosaccharomyces pombe. Thus, a single gene for glycyl-tRNA synthetase likely encodes both cytoplasmic and mitochondrial activities in most or all yeast. Phylogenetic analysis shows that GlyRS2 is a predecessor of all yeast GlyRS homologues. Thus, GRS1 appears to be the result of a duplication of GRS2, which itself is pseudogene-like.
在酿酒酵母中，有两个基因（GRS1和GRS2）分别编码甘氨酰 - tRNA合成酶（GlyRS1和GlyRS2）。GlyRS2的59%序列与GlyRS1相同。其他人曾提出GRS1和GRS2分别编码细胞质和线粒体中的酶。在这项研究中，我们发现GRS1编码这两种功能，而GRS2是可有可无的。此外，粟酒裂殖酵母中唯一已知的甘氨酰 - tRNA合成酶基因的表达可互补酿酒酵母中GRS1敲除等位基因的细胞质和线粒体表型。因此，在大多数或所有酵母中，一个甘氨酰 - tRNA合成酶基因可能同时编码细胞质和线粒体活性。系统发育分析表明，GlyRS2是所有酵母GlyRS同源物的前身。因此，GRS1似乎是GRS2复制的结果，而GRS2本身类似假基因。
