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Species‐specific differences in the regulation of the aminoacylation activity of mammalian tryptophanyl‐tRNA synthetases
Author(s) -
Wakasugi Keisuke
Publication year - 2010
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2009.11.073
Subject(s) - aminoacylation , mutant , transfer rna , biochemistry , mutagenesis , aminoacyl trna synthetase , biology , chemistry , rna , gene
Tryptophanyl‐tRNA synthetases (TrpRSs) catalyze the aminoacylation of tRNA Trp . Previously, I demonstrated that Zn 2+ ‐depleted human TrpRS is enzymatically inactive and that binding of Zn 2+ 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 Zn 2+ 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 Zn 2+ 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.