Isolation and characterization of the yeast gene coding for the alpha subunit of mitochondrial phenylalanyl-tRNA synthetase.
Isolation and characterization of the yeast gene coding for the alpha subunit of mitochondrial phenylalanyl-tRNA synthetase.
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DOI：
10.1016/s0021-9258(18)61410-3
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发表时间：
1987-03
期刊：
影响因子：
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通讯作者：
T. Koerner;A. Myers;S. Lee;A. Tzagoloff
中科院分区：
文献类型：
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作者：
T. Koerner;A. Myers;S. Lee;A. Tzagoloff
被分配到互补组G120的酿酒酵母的pet突变体的呼吸缺陷已被归因于它们不能酰化线粒体苯丙氨酰tRNA。通过用来自该互补组的代表性突变体的酵母基因组重组文库转化，克隆了能够互补G120突变体的遗传损伤的野生型酵母基因组DNA片段。命名为MSF 1的基因已在2.2-脱氢酶对片段上亚克隆，并测定了其核苷酸序列。MSF 1的预测蛋白产物具有55，314的分子量，并且具有与大肠杆菌苯丙氨酰-tRNA合成酶的α亚基高度一级序列同源性的几个结构域。基于G120突变体的表型和与细菌蛋白的同源性，提出MSF 1编码酵母线粒体苯丙氨酰-tRNA合成酶的α亚基。破坏的染色体拷贝的MSF 1在酿酒能力的单倍体菌株W303-1B诱导的表型类似于G120突变体，但不影响细胞活力，表明细胞质的苯丙氨酰-tRNA合成酶的酵母是由一个单独的基因编码。虽然E.大肠杆菌和酵母线粒体氨酰-tRNA合成酶在它们的一级序列上足够相似，从而表明它们具有共同的进化起源，它们经历了显著的变化，如在多肽链的某些区域中的低同源性和在线粒体酶中存在细菌苯丙氨酰-tRNA合成酶中缺乏的两个结构域所证明的。
The respiratory defect of pet mutants of Saccharomyces cerevisiae assigned to complementation group G120 has been ascribed to their inability to acylate the mitochondrial phenylalanyl tRNA. A fragment of wild type yeast genomic DNA capable of complementing the genetic lesion of G120 mutants has been cloned by transformation with a yeast genomic recombinant library of a representative mutant from this complementation group. The gene designated as MSF1 has been subcloned on a 2.2-kilobase pair fragment and its nucleotide sequence determined. The predicted protein product of MSF1 has a molecular weight of 55,314 and has several domains of high primary sequence homology to the alpha subunit of the Escherichia coli phenylalanyl-tRNA synthetase. Based on the phenotype of G120 mutants and the homology to the bacterial protein, MSF1 is proposed to code for the alpha subunit of yeast mitochondrial phenylalanyl-tRNA synthetase. Disruption of the chromosomal copy of MSF1 in the respiratory-competent haploid strain W303-1B induces a phenotype similar to G120 mutants but does not affect cell viability, indicating that the cytoplasmic phenylalanyl-tRNA synthetase of yeast is encoded by a separate gene. Although the E. coli and yeast mitochondrial aminoacyl-tRNA synthetases are sufficiently similar in their primary sequences to suggest a common evolutionary origin, they have undergone significant changes as evidenced by the low homology in some regions of the polypeptide chains and the presence in the mitochondrial enzyme of two domains that are lacking in the bacterial phenylalanyl-tRNA synthetase.