Biopolymers and cell. 2005; 21 (5): 400 - 406

Investigation of non-canonical complexes of eukaryotic elongation factor 1A with tRNA^Tyr and tyrosyl-tRNA synthetase. Role of different domains of the synthetase in interaction with tRNA.

P. V. Futernyk, K. Olszak, A. Przykorska, A. I. Kornelyuk, B. S. Negrutskii

A role of different domains of bovine tyrosil-tRNA synthetase (TyrRS) in the interaction with homologous tRNA has been determined by the method of tRNA band retardation in polyacrylamide gel. The site of TyrRS responsible for the binding of tRNA^Tyr is found to be formed mostly by the catalytic domain of TyrRS (TyrRS-DC). At the same time, the full-length TyrRS is found to bind tRNA stronger than TyrRS-DC. Cytokine-like C-domain of TyrRS also has tRNA-binding properties but much weaker than TyrRS-DC suggesting its possible involvement in tRNA binding as well. The formation of non-canonical ternary complex of tRNA^Tyr and eEF1A*GDP has been shown. Also, the formation of quaternary complex of eEF1A*GDP*tRNA^Tyr*TyrRS is detected. The catalytic domain of TyrRS appears to be responsible for this interaction, because the TyrRS-DC also is found to form the complex with eEF1A*GDP*tRNA^Tyr. These data support the universality of the tRNA channeling mechanism.

Key words: eukaryotic elongation factor 1A, tRNA^Tyr, tyrosyl-tRNA synthetase.