Tyrosyl-tRNA synthetase from bovine liver: study of the functional role of histidyl residues

D. V. Gnatenko, A. I. Kornelyuk, G. Kh. Matsuka

Institute of Molecular Biology and Genetics, Academy of Sciences of the Ukrainian SSR, Kiev

Abstract: A specific chemical modification of histidyl residues in tyrosyl-tRNA synthetase by diethyl pyrocarbonate was performed. It is shown that five of sixteen histidyl residues can react with diethyl pyrocarbonate in the native conditions. Modification of two histidyl residues per dimer results in the inactivation of tyrosyl-tRNA synthetase in both steps of the tRNA^Tyr aminoacylation. All substrates protect tyrosyl-tRNA synthetase against inactivation with diethyl pyrocarbonate, the most effective protector being combination of ATP and tyrosine. Histidyl residues of tyrosyl-tRNA synthetase are suggested to be involved in the catalytic mechanism of aminoacylation of tRNA^Tyr.

Russian Journal of Bioorganic Chemistry 1991, 17 (8):1033-1037

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