The role of divalent cations in the reactions of valyl transfer ribonucleic acid synthetase of Escherichia coli. Effects of spermine and ethylenediaminetetraacetate.
We have analyzed the function of spermine in the aminoacylation of tRNA-Val by the valyl-tRNA synthetase of Escherichia coli. Our results indicate that Mg2+ is required for the aminoacylation reaction as well as for the ATP-PP-i exchange catalyzed by this enzyme. The apparent stimulation by spermine is a function of the tRNA used, which appears to contain bound cations even after dialysis against 10 minus 4 M EDTA. Higher concentrations of EDTA totally abolish spermine-stimulated esterification of tRNA-Val.
D000604:Amino Acyl-tRNA Synthetases / Q000378:metabolism*; D004492:Edetic Acid / Q000494:pharmacology*; D004926:Escherichia coli / Q000201:enzymology*; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology*; D013096:Spermine / Q000494:pharmacology*; D014637:Valine-tRNA Ligase / Q000378:metabolism*
D013096:Spermine; D004492:Edetic Acid; D000604:Amino Acyl-tRNA Synthetases; D014637:Valine-tRNA Ligase; D008274:Magnesium