The role of divalent cations in the reactions of valyl transfer ribonucleic acid synthetase of Escherichia coli. Effects of spermine and ethylenediaminetetraacetate

J Biol Chem. 1975 May 25;250(10):3861-5.

Abstract

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.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acyl-tRNA Synthetases / metabolism*
  • Edetic Acid / pharmacology*
  • Escherichia coli / enzymology*
  • Kinetics
  • Magnesium / pharmacology*
  • Spermine / pharmacology*
  • Valine-tRNA Ligase / metabolism*

Substances

  • Spermine
  • Edetic Acid
  • Amino Acyl-tRNA Synthetases
  • Valine-tRNA Ligase
  • Magnesium