Function of the extra 5'-phosphate carried by histidine tRNA.
Among elongator tRNAs, tRNA specific for histidine has the peculiarity to possess one extra nucleotide at position -1. This nucleotide is believed to be responsible for recognition by histidyl-tRNA synthetase. Here, we show that, in fact, it is the phosphate 5' to the extra nucleotide which mainly supports the efficiency of the tRNA aminoacylation reaction catalyzed by Escherichia coli histidyl-tRNA synthetase. In the case of the reaction of E. coli peptidyl-tRNA hydrolase, this atypical phosphate is dispensable. Instead, peptidyl-tRNA hydrolase recognizes the phosphate of the phosphodiester bond between residues -1 and +1 of tRNA(His). Recognition of the +1 phosphate of tRNA(His) by peptidyl-tRNA hydrolase resembles, therefore, that of the 5'-terminal phosphate of other elongator tRNAs.
Fromant
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M
Laboratoire de Biochimie, Unité Mixte de Recherche No. 7654, Ecole Polytechnique, CNRS, 91128 Palaiseau Cedex, France.
Plateau
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P
Blanquet
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D000818:Animals; D001665:Binding Sites; D004926:Escherichia coli; D006643:Histidine-tRNA Ligase / Q000737:chemistry* / Q000378:metabolism; D010710:Phosphates; D012354:RNA, Transfer, His / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D010710:Phosphates; D012354:RNA, Transfer, His; D006643:Histidine-tRNA Ligase