Species‐specific differences in the regulation of the aminoacylation activity of mammalian tryptophanyl‐tRNA synthetases
Species‐specific differences in the regulation of the aminoacylation activity of mammalian tryptophanyl‐tRNA synthetases
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DOI：
10.1016/j.febslet.2009.11.073
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发表时间：
2010-01
期刊：
影响因子：
3.5
通讯作者：
K. Wakasugi
中科院分区：
文献类型：
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作者：
K. Wakasugi
色氨酸- trna合成酶（TrpRSs）催化tRNATrp的氨基酰化。先前，我证明了Zn2+耗尽的人类trpr具有酶活性，Zn2+或血红素与人类trpr结合会刺激其氨基酰化活性。在本研究中，牛和小鼠的trprs被发现具有组成性活性，无论是否存在Zn2+或铁原卟啉IX氯。诱变实验表明，人类H130R突变体具有组成性活性，牛R135H、E438A双突变体与Zn2+或血红素结合，增强其氨基酰化活性，与人类野生型trpr一样。这些结果为trpr活性的物种特异性调控提供了第一个证据。
Tryptophanyl-tRNA synthetases (TrpRSs) catalyze the aminoacylation of tRNATrp. Previously, I demonstrated that Zn2+-depleted human TrpRS is enzymatically inactive and that binding of Zn2+or heme to human TrpRS stimulates its aminoacylation activity. In the present study, bovine and mouse TrpRSs were found to be constitutively active regardless of the presence of Zn2+or ferriprotoporphyrin IX chloride. Mutagenesis experiments demonstrated that the human H130R mutant is constitutively active and that the bovine R135H, E438A double mutant binds with Zn2+or heme to enhance its aminoacylation activity as does human wild-type TrpRS. These results provide the first evidence of species-specific regulation of TrpRS activity.