Expression and characterization of the human mitochondrial leucyl-tRNA synthetase
Expression and characterization of the human mitochondrial leucyl-tRNA synthetase
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DOI：
10.1016/s0167-4781(99)00240-7
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发表时间：
2000-02-29
期刊：
影响因子：
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通讯作者：
Spremulli, LL
中科院分区：
文献类型：
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作者：
Bullard, JM;Cai, YC;Spremulli, LL
已从EST数据库中鉴定出编码人线粒体亮氨酰-tRNA合成酶（mtLeuRS）的cDNA克隆。对该cDNA编码的蛋白质的分析表明，该蛋白质的长度为903个氨基酸，并含有一个线粒体信号序列，该序列预计包含前21个氨基酸。序列分析表明，这种蛋白质含有I类氨酰-tRNA合成酶的特征基序和与其他线粒体和细菌LeuRS蛋白质高度同源的区域。该蛋白的成熟形式已被克隆并在大肠杆菌中表达。凝胶过滤表明，人mtLeuRS在单体状态下具有活性，表观分子量为101 kDa。colitRNA（Leu）。其活性在高水平的单价或二价阳离子下受到抑制。K-M和K（猫）值ATP：PPi交换和氨酰化反应已被确定。(C)2000 Elsevier Science B. V.保留所有权利。
A cDNA clone encoding the human mitochondrial leucyl-tRNA synthetase (mtLeuRS) has been identified from the EST databases. Analysis of the protein encoded by this cDNA indicates that the protein is 903 amino acids in length and contains a mitochondrial signal sequence that is predicted to encompass the first 21 amino acids. Sequence analysis shows that this protein contains the characteristic motifs of class I aminoacyl-tRNA synthetases and regions of high homology to other mitochondrial and bacterial LeuRS proteins. The mature form of this protein has been cloned and expressed in Escherichia coli. Gel filtration indicates that human mtLeuRS is active in a monomeric state, with an apparent molecular mass of 101 kDa, The human mtLeuRS is capable of aminoacylating E. coli tRNA(Leu). Its activity is inhibited at high levels of either monovalent or divalent cations. K-M and k(cat) values for ATP:PPi exchange and for the aminoacylation reaction have been determined. (C) 2000 Elsevier Science B.V. All rights reserved.